Method of operating an articulating ultrasonic surgical instrument

ABSTRACT

An apparatus comprises a body assembly, a shaft, an acoustic waveguide, an articulation section, an end effector, and an articulation drive assembly. The shaft extends distally from the body assembly and defines a longitudinal axis. The acoustic waveguide comprises a flexible portion. The articulation section is coupled with the shaft. A portion of the articulation section encompasses the flexible portion of the waveguide. The articulation section comprises a plurality of body portions aligned along the longitudinal axis and a flexible locking member. The flexible locking member is operable to secure the body portions in relation to each other and in relation to the shaft. The end effector comprises an ultrasonic blade in acoustic communication with the waveguide. The articulation drive assembly is operable to drive articulation of the articulation section to thereby deflect the end effector from the longitudinal axis.

PRIORITY

This application claims priority to U.S. Provisional Pat. App. No.62/176,880, entitled “Ultrasonic Surgical Device with Articulating EndEffector,” filed Apr. 22, 2014, the disclosure of which is incorporatedby reference herein.

BACKGROUND

A variety of surgical instruments include an end effector having a bladeelement that vibrates at ultrasonic frequencies to cut and/or sealtissue (e.g., by denaturing proteins in tissue cells). These instrumentsinclude piezoelectric elements that convert electrical power intoultrasonic vibrations, which are communicated along an acousticwaveguide to the blade element. The precision of cutting and coagulationmay be controlled by the surgeon's technique and adjusting the powerlevel, blade edge, tissue traction and blade pressure.

Examples of ultrasonic surgical instruments include the HARMONIC ACE®Ultrasonic Shears, the HARMONIC WAVE® Ultrasonic Shears, the HARMONICFOCUS® Ultrasonic Shears, and the HARMONIC SYNERGY® Ultrasonic Blades,all by Ethicon Endo-Surgery, Inc. of Cincinnati, Ohio. Further examplesof such devices and related concepts are disclosed in U.S. Pat. No.5,322,055, entitled “Clamp Coagulator/Cutting System for UltrasonicSurgical Instruments,” issued Jun. 21, 1994, the disclosure of which isincorporated by reference herein; U.S. Pat. No. 5,873,873, entitled“Ultrasonic Clamp Coagulator Apparatus Having Improved Clamp Mechanism,”issued Feb. 23, 1999, the disclosure of which is incorporated byreference herein; U.S. Pat. No. 5,980,510, entitled “Ultrasonic ClampCoagulator Apparatus Having Improved Clamp Arm Pivot Mount,” filed Oct.10, 1997, the disclosure of which is incorporated by reference herein;U.S. Pat. No. 6,325,811, entitled “Blades with Functional BalanceAsymmetries for use with Ultrasonic Surgical Instruments,” issued Dec.4, 2001, the disclosure of which is incorporated by reference herein;U.S. Pat. No. 6,773,444, entitled “Blades with Functional BalanceAsymmetries for Use with Ultrasonic Surgical Instruments,” issued Aug.10, 2004, the disclosure of which is incorporated by reference herein;and U.S. Pat. No. 6,783,524, entitled “Robotic Surgical Tool withUltrasound Cauterizing and Cutting Instrument,” issued Aug. 31, 2004,the disclosure of which is incorporated by reference herein.

Still further examples of ultrasonic surgical instruments are disclosedin U.S. Pub. No. 2006/0079874, now abandoned, entitled “Tissue Pad forUse with an Ultrasonic Surgical Instrument,” published Apr. 13, 2006,the disclosure of which is incorporated by reference herein; U.S. Pub.No. 2007/0191713, now abandoned, entitled “Ultrasonic Device for Cuttingand Coagulating,” published Aug. 16, 2007, the disclosure of which isincorporated by reference herein; U.S. Pub. No. 2007/0282333, nowabandoned, entitled “Ultrasonic Waveguide and Blade,” published Dec. 6,2007, the disclosure of which is incorporated by reference herein; U.S.Pub. No. 2008/0200940, now abandoned, entitled “Ultrasonic Device forCutting and Coagulating,” published Aug. 21, 2008, the disclosure ofwhich is incorporated by reference herein; U.S. Pat. No. 8,623,027,entitled “Ergonomic Surgical Instruments,” issued Jan. 7, 2014, thedisclosure of which is incorporated by reference herein; U.S. Pub. No.2010/0069940, entitled “Ultrasonic Device for Fingertip Control,”published Mar. 18, 2010, issued as U.S. Pat. No. 9,023,071 on May 5,2015, the disclosure of which is incorporated by reference herein; andU.S. Pat. No. 8,461,744, entitled “Rotating Transducer Mount forUltrasonic Surgical Instruments,” published Jan. 20, 2011, thedisclosure of which is incorporated by reference herein; and U.S. Pat.No. 8,591,536, entitled “Ultrasonic Surgical Instrument Blades,”published Feb. 2, 2012, the disclosure of which is incorporated byreference herein.

Some ultrasonic surgical instruments may include a cordless transducersuch as that disclosed in U.S. Pub. No. 2012/0112687, entitled “RechargeSystem for Medical Devices,” published May 10, 2012, issued as U.S. Pat.No. 9,381,058 on Jul. 5, 2016, the disclosure of which is incorporatedby reference herein; U.S. Pub. No. 2012/0116265, entitled “SurgicalInstrument with Charging Devices,” published May 10, 2012, thedisclosure of which is incorporated by reference herein; and/or U.S.Pat. App. No. 61/410,603, filed Nov. 5, 2010, entitled “Energy-BasedSurgical Instruments,” the disclosure of which is incorporated byreference herein.

Additionally, some ultrasonic surgical instruments may include anarticulating shaft section and/or a bendable ultrasonic waveguide.Examples of such ultrasonic surgical instruments are disclosed in U.S.Pat. No. 5,897,523, entitled “Articulating Ultrasonic SurgicalInstrument,” issued Apr. 27, 1999, the disclosure of which isincorporated by reference herein; U.S. Pat. No. 5,989,264, entitled“Ultrasonic Polyp Snare,” issued Nov. 23, 1999, the disclosure of whichis incorporated by reference herein; U.S. Pat. No. 6,063,098, entitled“Articulable Ultrasonic Surgical Apparatus,” issued May 16, 2000, thedisclosure of which is incorporated by reference herein; U.S. Pat. No.6,090,120, entitled “Articulating Ultrasonic Surgical Instrument,”issued Jul. 18, 2000, the disclosure of which is incorporated byreference herein; U.S. Pat. No. 6,454,782, entitled “Actuation Mechanismfor Surgical Instruments,” issued Sep. 24, 2002, the disclosure of whichis incorporated by reference herein; U.S. Pat. No. 6,589,200, entitled“Articulating Ultrasonic Surgical Shears,” issued Jul. 8, 2003, thedisclosure of which is incorporated by reference herein; U.S. Pat. No.6,752,815, entitled “Method and Waveguides for Changing the Direction ofLongitudinal Vibrations,” issued Jun. 22, 2004, the disclosure of whichis incorporated by reference herein; U.S. Pat. No. 7,135,030, entitled“Articulating Ultrasonic Surgical Shears,” issued Nov. 14, 2006; U.S.Pat. No. 7,621,930, entitled “Ultrasound Medical Instrument Having aMedical Ultrasonic Blade,” issued Nov. 24, 2009, the disclosure of whichis incorporated by reference herein; U.S. Pub. No. 2014/0005701,published Jan. 2, 2014, issued as U.S. Pat. No. 9,393,037 on Jul. 19,2016, entitled “Surgical Instruments with Articulating Shafts,” thedisclosure of which is incorporated by reference herein; U.S. Pub. No.2014/0005703, entitled “Surgical Instruments with Articulating Shafts,”published Jan. 2, 2014, issued as U.S. Pat. No. 9,408,622 on Aug. 9,2016, the disclosure of which is incorporated by reference herein; U.S.Pub. No. 2014/0114334, entitled “Flexible Harmonic Waveguides/Blades forSurgical Instruments,” published Apr. 24, 2014, issued as U.S. Pat. No.9,095,367 on Aug. 4, 2015 the disclosure of which is incorporated byreference herein; U.S. Pub. No. 2015/0080924, entitled ““ArticulationFeatures for Ultrasonic Surgical Instrument,” published Mar. 19, 2015,issued as U.S. Pat. No. 9,936,949 on Nov. 15, 2018, the disclosure ofwhich is incorporated by reference herein; and U.S. patent applicationSer. No. 14/258,179, entitled Ultrasonic Surgical Device withArticulating End Effector,” filed Apr. 22, 2014, disclosure of which isincorporated by reference herein.

While several surgical instruments and systems have been made and used,it is believed that no one prior to the inventors has made or used theinvention described in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

While the specification concludes with claims which particularly pointout and distinctly claim this technology, it is believed this technologywill be better understood from the following description of certainexamples taken in conjunction with the accompanying drawings, in whichlike reference numerals identify the same elements and in which:

FIG. 1 depicts a side elevational view of an exemplary ultrasonicsurgical instrument;

FIG. 2 depicts a perspective view of an articulation section of a shaftassembly and an end effector of the surgical instrument of FIG. 1;

FIG. 3 depicts an exploded perspective view of an articulation sectionof the shaft assembly of FIG. 2;

FIG. 4 depicts a cross-sectional side view of the shaft assembly and endeffector of FIG. 2;

FIG. 5 depicts a top plan view of the shaft assembly and end effector ofFIG. 2;

FIG. 6A depicts a cross-sectional top view of the shaft assembly and endeffector of FIG. 2 in a straight configuration;

FIG. 6B depicts a cross-sectional top view of the shaft assembly and endeffector of FIG. 2 in an articulated configuration;

FIG. 7 depicts a partially exploded perspective view of the shaftassembly and end effector of FIG. 2;

FIG. 8 depicts a perspective view of a distal collar and a drive cableof the shaft assembly of FIG. 2;

FIG. 9 depicts a partially exploded perspective view of an articulationcontrol assembly of the instrument of FIG. 1;

FIG. 10A depicts a side elevational view of an exemplary alternative endeffector and the distal portion of a shaft assembly, configured forincorporation in the instrument of FIG. 1, with a clamp arm of the endeffector in a closed position, and with an outer sheath shown incross-section to reveal components within the outer sheath;

FIG. 10B depicts a side elevational view of the shaft assembly and endeffector of FIG. 10A, with the clamp arm moved to a partially openposition;

FIG. 10C depicts a side elevational view of the shaft assembly and endeffector of FIG. 10A, with the clamp arm moved to a fully open position;

FIG. 11A depicts a side elevational view of another exemplaryalternative end effector and the distal portion of a shaft assembly andend effector, configured for incorporation in the instrument of FIG. 1,with a clamp arm of the end effector in a closed position, and with theshaft assembly shown in side cross-section;

FIG. 11B depicts a side elevational view of the shaft assembly and endeffector of FIG. 11A, with the clamp arm moved to an open position, andwith the shaft assembly shown in side cross-section;

FIG. 12A depicts a top plan view of the shaft assembly and end effectorof FIG. 11A in a substantially straight configuration, with the shaftassembly shown in top cross-section;

FIG. 12B depicts a top plan view of the shaft assembly and end effectorof FIG. 11A in an articulated configuration, with the shaft assemblyshown in top cross-section;

FIG. 13A depicts a side elevational view of yet another exemplaryalternative end effector and the distal portion of a shaft assembly andend effector, configured for incorporation in the instrument of FIG. 1,with a clamp arm of the end effector in a closed position, and with theshaft assembly shown in side cross-section;

FIG. 13B depicts a side elevational view of the shaft assembly and endeffector of FIG. 13A, with the clamp arm moved to an open position, andwith the shaft assembly shown in side cross-section;

FIG. 14A depicts a top plan view of the shaft assembly and end effectorof FIG. 13A in a substantially straight configuration, with the shaftassembly shown in top cross-section;

FIG. 14B depicts a top plan view of the shaft assembly and end effectorof FIG. 13A in an articulated configuration, with the shaft assemblyshown in top cross-section;

FIG. 15A depicts a side elevational view of yet another exemplaryalternative end effector and the distal portion of a shaft assembly andend effector, configured for incorporation in the instrument of FIG. 1,with a clamp arm of the end effector in a closed position, and with theshaft assembly shown in side cross-section;

FIG. 15B depicts a side elevational view of the shaft assembly and endeffector of FIG. 15A, with the clamp arm moved to an open position, andwith the shaft assembly shown in side cross-section;

FIG. 16A depicts a top plan view of the shaft assembly and end effectorof FIG. 15A in a substantially straight position, with the shaftassembly shown in top cross-section;

FIG. 16B depicts a top plan view of the shaft assembly and end effectorof FIG. 15A moved into a bent configuration, with the shaft assemblyshown in top cross-section;

FIG. 17A depicts a perspective view of yet another exemplary alternativeend effector and the distal portion of a shaft assembly and endeffector, configured for incorporation in the instrument of FIG. 1, witha clamp arm of the end effector in a closed position;

FIG. 17B depicts a perspective view of the shaft assembly and endeffector of FIG. 17A, with the clamp arm moved to an open position;

FIG. 18 depicts a side cross-sectional view of the shaft assembly andend effector of FIG. 17A, with the clamp arm in the open position;

FIG. 19 depicts a front cross-sectional end view of yet anotherexemplary alternative shaft assembly and end effector, configured forincorporation in the instrument of FIG. 1;

FIG. 20 depicts a front cross-sectional end view of yet anotherexemplary alternative shaft assembly and end effector, configured forincorporation in the instrument of FIG. 1;

FIG. 21 depicts a front cross-sectional end view of yet anotherexemplary alternative shaft assembly and end effector, configured forincorporation in the instrument of FIG. 1;

FIG. 22 depicts a front cross-sectional end view of yet anotherexemplary alternative shaft assembly and end effector, configured forincorporation in the instrument of FIG. 1;

FIG. 23 depicts a front cross-sectional end view of yet anotherexemplary alternative shaft assembly and end effector, configured forincorporation in the instrument of FIG. 1;

FIG. 24 depicts a front cross-sectional end view of yet anotherexemplary alternative shaft assembly and end effector, configured forincorporation in the instrument of FIG. 1;

FIG. 25 depicts a front cross-sectional end view of yet anotherexemplary alternative shaft assembly and end effector, configured forincorporation in the instrument of FIG. 1;

FIG. 26 depicts a front cross-sectional end view of yet anotherexemplary alternative shaft assembly and end effector, configured forincorporation in the instrument of FIG. 1;

FIG. 27 depicts a front cross-sectional end view of yet anotherexemplary alternative shaft assembly and end effector, configured forincorporation in the instrument of FIG. 1;

FIG. 28 depicts a front end view of a clamp arm coupled with anexemplary push/pull cable assembly configured for incorporation in anyof the shaft assemblies and end effectors described herein;

FIG. 29 depicts a side elevational view of the push/pull cable assemblyof FIG. 28;

FIG. 30 depicts a perspective view of an exemplary alternative push/pullcable assembly configured for incorporation in any of the shaftassemblies and end effectors described herein;

FIG. 31 depicts a perspective view of another exemplary alternativepush/pull cable configured for incorporation in any of the shaftassemblies and end effectors described herein;

FIG. 32 depicts a perspective view of an exemplary clamp configured forincorporation in any of the end effectors described herein;

FIG. 33A depicts a side elevational view of an end effector having theclamp arm of FIG. 32, with the clamp arm in a closed position;

FIG. 33B depicts a side elevational view of the end effector of FIG.33A, with the clamp arm moved to an open position;

FIG. 34A depicts a cross-sectional top view of a distal portion of yetanother exemplary alternative shaft assembly and end effector configuredfor incorporation in the instrument of FIG. 1, with the shaft assemblyand end effector in a substantially straight configuration;

FIG. 34B depicts a cross-sectional top view of the shaft assembly andend effector of FIG. 34A moved into an articulated configuration;

FIG. 35 depicts a cross-sectional view of the shaft assembly of FIG.34A, taken along line 35-35 of FIG. 34A;

FIG. 36 depicts a side elevational view of an exemplary relationshipbetween articulation bands and the clamp arm of the shaft assembly andend effector of FIG. 34A;

FIG. 37 depicts a side elevational view of another exemplaryrelationship between articulation bands and the clamp arm of the shaftassembly and end effector of FIG. 34A;

FIG. 38 depicts a cross-sectional side view of yet another exemplaryalternative shaft assembly and end effector configured for incorporationin the instrument of FIG. 1;

FIG. 39 depicts an exploded perspective view of the shaft assembly ofFIG. 38;

FIG. 40 depicts a detailed perspective view of yet another exemplaryalternative shaft and end effector assembly configured for incorporationin the instrument of FIG. 1;

FIG. 41 depicts a perspective view of components of yet anotherexemplary alternative shaft assembly configured for incorporation in theinstrument of FIG. 1;

FIG. 42A depicts a top plan view of the shaft assembly of FIG. 41 in astraight configuration;

FIG. 42B depicts a top plan view of the shaft assembly of FIG. 41 in anarticulated configuration;

FIG. 43 depicts a perspective view of an exemplary alternative waveguideconfigured for incorporation in the instrument of FIG. 1;

FIG. 44 depicts a cross-sectional top view of a flange of the waveguideof FIG. 43;

FIG. 45 depicts a detailed perspective view of the flange of FIG. 44;

FIG. 46 depicts a cross-sectional end view of the flange of FIG. 44;

FIG. 47 depicts a detailed perspective view of an exemplary alternativeflange;

FIG. 48 depicts a cross-sectional end view of the flange of FIG. 47;

FIG. 49 depicts a detailed perspective view of another exemplaryalternative flange;

FIG. 50 depicts a cross-sectional end view of the flange of FIG. 49;

FIG. 51 depicts a side elevational view of an exemplary alternativeultrasonic surgical instrument;

FIG. 52 depicts an enlarged side elevational view of an exemplaryarticulation control assembly of the instrument of FIG. 51, with ahousing of the assembly shown in cross-section;

FIG. 53 depicts a top plan view of the articulation control assembly ofFIG. 52, with the housing of the assembly shown in cross-section, andthe end effector of the instrument of FIG. 51;

FIG. 54 depicts a side elevational view of an exemplary alternativeultrasonic surgical instrument;

FIG. 55A depicts a perspective view of an articulation section of anexemplary alternative shaft assembly and an end effector that may beincorporated into the instrument of FIG. 1;

FIG. 55B depicts a perspective view of the articulation section of theshaft assembly and the end effector of FIG. 55A with certain elementsomitted to show greater detail;

FIG. 55C depicts a perspective view of the articulation section of theshaft assembly and the end effector of FIG. 55A with certain elementsomitted to show greater detail;

FIG. 55D depicts a perspective view of the articulation section of theshaft assembly and the end effector of FIG. 55A with certain elementsomitted to show greater detail;

FIG. 56 depicts an exploded perspective view of the articulation sectionof FIG. 55A;

FIG. 57 depicts a perspective view of a retention collar of thearticulation section of FIG. 55A;

FIG. 58 depicts a top elevational view of the retention collar of FIG.55A;

FIG. 59 depicts a perspective view of a flexible locking feature of thearticulation section of FIG. 55A;

FIG. 60 depicts a front elevational view of the flexible locking featureof FIG. 55A;

FIG. 61 depicts a perspective view of body portions of the articulationsection of FIG. 55A longitudinally aligned with one another;

FIG. 62 depicts a perspective view of the intermediate body portion ofFIG. 55A;

FIG. 63 depicts a front elevational view of the intermediate bodyportion of FIG. 55A;

FIG. 64 depicts a perspective view of the distal body portion of FIG.55A;

FIG. 65 depicts a side elevational view of the distal body portion ofFIG. 55A;

FIG. 66 depicts a perspective view of the proximal body portion of FIG.55A;

FIG. 67 depicts a cross sectional view of the articulation section ofFIG. 55A across the intermediate body portion;

FIG. 68 depicts a top elevational view of the articulation section ofthe shaft assembly and the end effector of the surgical instrument ofFIG. 55A;

FIG. 69A depicts a cross sectional top view of the articulation sectionof the shaft assembly of the surgical instrument of FIG. 55A, with thearticulation section in a non-articulated state;

FIG. 69B depicts a cross sectional top view of the articulation sectionof the shaft assembly of the surgical instrument of FIG. 55A, with thearticulation section in an articulated state;

FIG. 70 depicts a perspective view of an exemplary distal node bumperthat may be incorporated into the shaft assembly of FIG. 2;

FIG. 71 depicts a front elevational view of the distal node bumper ofFIG. 70;

FIG. 72 depicts a front elevational view of tissue clamped between anexemplary keyhole blade and clamp arm assembly that may be incorporatedinto the end effector of FIG. 2, in an on-plane configuration;

FIG. 73 depicts a front elevational view of tissue clamped between thekeyhole blade and clamp arm assembly of FIG. 71, in a first off-planeconfiguration;

FIG. 74 depicts a front elevational view of tissue clamped between thekeyhole blade and clamp arm assembly of FIG. 71, in a second off-planeconfiguration;

FIG. 75 shows a perspective view of an exemplary alternativearticulation control assembly that may be incorporated into theinstrument of FIG. 1, with a locking feature in a locked configuration;

FIG. 76A depicts a top plan view of the articulation control assembly ofFIG. 75, with the locking feature in the locked configuration;

FIG. 76B depicts a top plan view of the articulation control assembly ofFIG. 75, with the locking feature in an unlocked configuration;

FIG. 77 depicts a side elevational view of another exemplary alternativearticulation control assembly that may be incorporated into theinstrument of FIG. 1, with a locking feature in a locked configuration;

FIG. 77A depicts a detailed side elevational view of the locking featureof the articulation control assembly of FIG. 77 in the lockedconfiguration;

FIG. 77B depicts a detailed side elevational view of the locking featureof the articulation control assembly of FIG. 77 in the unlockedconfiguration;

FIG. 78 depicts a bottom cross-sectional view of a knob of thearticulation control assembly of FIG. 77, taken along line 78-78 of FIG.77;

FIG. 79A depicts a side elevational view of yet another exemplaryalternative articulation control assembly that may be incorporated intothe instrument of FIG. 1, with a locking feature in a lockedconfiguration;

FIG. 79B depicts a side elevational view of the articulation controlassembly of FIG. 79A, with the locking feature in an unlockedconfiguration;

FIG. 80 a bottom plan view of a knob of the articulation controlassembly of FIG. 79A;

FIG. 81 depicts a top plan view of a housing of the articulation controlassembly of FIG. 79A;

FIG. 82 depicts a top elevational view of yet another exemplaryalternative articulation control assembly that may be incorporated intothe instrument of FIG. 1, with a locking feature in a lockedconfiguration;

FIG. 83A depicts a partial, side cross-sectional view of thearticulation control assembly of FIG. 82, with the locking feature in alocked configuration, with the cross section taken along line 83-83 ofFIG. 82;

FIG. 83B depicts a partial, side cross-sectional view of thearticulation control assembly of FIG. 82, with the locking feature in anunlocked configuration;

FIG. 84 depicts an exploded perspective view of another exemplaryalternative articulation control assembly that may be incorporated intothe instrument of FIG. 1;

FIG. 85 depicts a bottom perspective view of a knob of the articulationcontrol assembly of FIG. 84;

FIG. 86 depicts a perspective view of the articulation control assemblyof FIG. 84, with part of the housing broken away to show details of thecomponents;

FIG. 87 depicts another perspective view of the articulation controlassembly of FIG. 84, with part of the housing broken away to showdetails of the components;

FIG. 88A shows a rear elevational view of the articulation controlassembly of FIG. 84, with a portion of the housing hidden to showdetails of the components, and with the knob in a home position;

FIG. 88B shows a rear elevational view of the articulation controlassembly of FIG. 84, with a portion of the housing broken away to showdetails of the components, and with the knob tilted to the unlockingposition;

FIG. 89 shows a side elevational view of the articulation controlassembly of FIG. 84, with a portion of the housing being shown astransparent to show details of the components, and with the knob tiltedto the unlocking position;

FIG. 90A depicts a partial, schematic, side elevational view of anexemplary alternative articulation control assembly that may beincorporated into the instrument of FIG. 1, with a locking feature in alocked configuration;

FIG. 90B depicts a partial, schematic, side elevational view of thearticulation control assembly of FIG. 90A, with the locking feature inan unlocked configuration;

FIG. 91A depicts a top plan view of another exemplary alternativearticulation control assembly that may be incorporated into theinstrument of FIG. 1, with the articulation control assembly in a firstconfiguration;

FIG. 91B depicts a top plan view of the articulation control assembly ofFIG. 91A, with the articulation control assembly in a secondconfiguration;

FIG. 92A depicts a partial side elevational view of the articulationcontrol assembly of FIG. 91A, with the articulation control assembly inthe first configuration, with the cross section taken along line 92A-92Aof FIG. 91A;

FIG. 92B depicts a partial side elevational view of the articulationcontrol assembly of FIG. 91A, with the articulation control assembly inthe second configuration, with the cross section taken along line92B-92B of FIG. 91B;

FIG. 93A depicts a side elevational view of another exemplaryalternative articulation control assembly that may be incorporated intothe instrument of FIG. 1, with the articulation control assembly in afirst configuration;

FIG. 93B depicts a side elevational view of the articulation controlassembly of FIG. 93A, with the articulation control assembly in a secondconfiguration;

FIG. 94A depicts a partial cross-sectional view of the articulationcontrol assembly of FIG. 93A, taken along line 94A-94A of FIG. 93A, withthe articulation control assembly in the first configuration;

FIG. 94B depicts a partial cross-sectional view of the articulationcontrol assembly of FIG. 93A, taken along line 94B-94B of FIG. 93B, withthe articulation control assembly in the second configuration;

FIG. 95 depicts a side elevational view of an exemplary electrosurgicalinstrument;

FIG. 96 depicts a perspective view of a partially assembled rotationlock feature that may be incorporated into the instrument of FIG. 1 orthe instrument of FIG. 95;

FIG. 97 depicts an enlarged perspective view of the partially assembledrotation lock feature of FIG. 96, with a housing half of the instrumenthandle assembly omitted;

FIG. 98 depicts a perspective view of the assembled rotation lockfeature of FIG. 96, positioned on a shaft assembly;

FIG. 99A depicts a cross sectional front view of the assembled rotationlock feature of FIG. 96 in a first unengaged position;

FIG. 99B depicts a cross sectional front view of the assembled rotationlock feature of FIG. 96 in a second unengaged position;

FIG. 99C depicts a cross sectional front view of the assembled rotationlock feature of FIG. 96 in a first engaged position;

FIG. 99D depicts a cross sectional front view of the assembled rotationlock feature of FIG. 96 in a second engaged position and rotated 90degrees;

FIG. 99E depicts a cross sectional front view of the assembled rotationlock feature of FIG. 96 in the first unengaged position but rotated 90degrees;

FIG. 100A depicts a side elevational view of another exemplaryalternative surgical instrument, with a partially assembled rotationlock feature in an unlocked position;

FIG. 100B depicts a side elevational view of the instrument of FIG.100A, with the partially assembled rotation lock feature in a lockedposition;

FIG. 101A depicts a top cross-sectional view of the instrument of FIG.100A, with the rotation lock feature in the unlocked position;

FIG. 101B depicts a top cross-sectional view of the instrument of FIG.100A, with the rotation lock feature in the locked position;

FIG. 102A depicts a top cross-sectional view of a partially assembledexemplary alternative rotation lock feature that may be incorporatedinto the instrument of FIG. 1 or the instrument of FIG. 95, with therotation lock feature in an unlocked position;

FIG. 102B depicts a top cross-sectional view of the partially assembledrotation lock feature of FIG. 102A in a locked position;

FIG. 103A depicts a top cross-sectional view of a partially assembledexemplary alternative rotation lock feature that may be incorporatedinto the instrument of FIG. 1 or the instrument of FIG. 95, with therotation lock feature in an unlocked position;

FIG. 103B depicts a top cross-sectional view of the partially assembledrotation lock feature of FIG. 103A in a locked position;

FIG. 104A depicts a top plan view of a modified version of the shaftassembly and end effector of FIG. 2 having an exemplary structuralfeature in a spaced-apart orientation;

FIG. 104B depicts a top plan view of the modified shaft assembly and endeffector of FIG. 104A with the structural feature of FIG. 104A in aclosed orientation;

FIG. 105 depicts a perspective view of another modified version of theshaft assembly and end effector of FIG. 2 having another exemplarystructural feature;

FIG. 106A depicts a cross-sectional top view of the modified shaftassembly and end effector of FIG. 105 in a straight configuration withthe structural feature of FIG. 105 deflated;

FIG. 106B depicts a cross-sectional top view of the modified shaftassembly and end effector of FIG. 105 in a straight configuration withthe structural feature of FIG. 105 inflated;

FIG. 106C depicts a cross-sectional top view of the modified shaftassembly and end effector of FIG. 105 in an articulated configurationwith the structural feature of FIG. 105 deflated;

FIG. 107 depicts a top plan view of another modified version of theshaft assembly and end effector of FIG. 2 having a plurality of couplerslinked to one another;

FIG. 108A depicts a top plan view of yet another exemplary structuralfeature that may be incorporated into the shaft assembly of FIG. 107, ina contracted configuration;

FIG. 108B depicts a top plan view of the structural feature of FIG. 108Ain an expanded configuration;

FIG. 109 depicts a top view of the shaft assembly and end effector ofFIG. 107 in a straight configuration with the structural feature of FIG.108A in the contracted configuration positioned therein;

FIG. 110A depicts detailed a top view of the shaft assembly of FIG. 107in a straight configuration with the structural feature of FIG. 108A inthe contracted configuration positioned therein;

FIG. 110B depicts detailed a top view of the shaft assembly of FIG. 107in a straight configuration with the structural feature of FIG. 108A inthe expanded configuration positioned therein;

FIG. 111A depicts a perspective view of a modified version of thearticulation control assembly of FIG. 9 in a first rotational positionand coupled with a linkage of the structural feature of FIG. 108A;

FIG. 111B depicts a perspective view of the modified articulationcontrol assembly of FIG. 111A moved into a second rotational position soas to translate the linkage of FIG. 111A;

FIG. 112 depicts a perspective view of yet another exemplary structuralfeature that may be incorporated into the shaft assembly and endeffector of FIG. 107;

FIG. 113 depicts a top plan view of the structural feature of FIG. 112;

FIG. 114A depicts detailed a top view of the shaft assembly of FIG. 107in a straight configuration with the structural feature of FIG. 112positioned therein in a first lateral position;

FIG. 114B depicts detailed a top view of the shaft assembly of FIG. 107in a straight configuration with the structural feature of FIG. 112positioned therein and moved to a second lateral position;

FIG. 115 depicts a top plan view of yet another exemplary structuralfeature that may be incorporated into the shaft assembly of FIG. 2;

FIG. 116A depicts a detailed top plan view of a modified version of theshaft assembly of FIG. 2 having a plurality of linkage members in astraight configuration with the structural feature of FIG. 115positioned therein in a distal longitudinal position;

FIG. 116B depicts a detailed top plan view of the modified shaftassembly of FIG. 116A having a plurality of linkage members in astraight configuration with the structural feature of FIG. 115positioned therein and moved into a proximal longitudinal position;

FIG. 116C depicts a detailed top plan view of the modified shaftassembly of FIG. 116A having a plurality of linkage members in anarticulated configuration with the structural feature of FIG. 115positioned therein in the proximal longitudinal position;

FIG. 117 depicts a perspective view of another modified version of theshaft assembly of FIG. 2 having yet another exemplary structural featurepositioned therein;

FIG. 118 depicts a top plan view of the structural feature of FIG. 117;

FIG. 119 depicts a cross-sectional front view of the stiffening featureof FIG. 117, taken along line 119-119 of FIG. 118;

FIG. 120 depicts an exemplary alternative cross-sectional front view ofthe stiffening feature of FIG. 117;

FIG. 121 depicts a cross-sectional front view of the modified shaftassembly of FIG. 117 with the structural feature of FIG. 117 positionedtherein, with the cross section taken along line 121-121 of FIG. 117;

FIG. 122A depicts a detailed cross-sectional top plan view of themodified shaft assembly of FIG. 117 in a straight configuration with thestructural feature of FIG. 117 positioned therein in a distallongitudinal position, with the cross section taken along line 122-122of FIG. 117;

FIG. 122B depicts a detailed cross-sectional top plan view of themodified shaft assembly of FIG. 117 in a straight configuration with thestructural feature of FIG. 117 positioned therein and moved into aproximal longitudinal position, with the cross section taken along line122-122 of FIG. 117;

FIG. 122C depicts a detailed cross-sectional top plan view of themodified shaft assembly of FIG. 117 in an articulated configuration withthe structural feature of FIG. 117 positioned therein in the proximallongitudinal position, with the cross section taken along line 122-122of FIG. 117;

FIG. 123 depicts a perspective view of yet another exemplary structuralfeature that may be incorporated into the shaft assembly of FIG. 2;

FIG. 124 depicts a cross-sectional front view of the rigidizing memberof FIG. 123, taken along line 124-124 of FIG. 123;

FIG. 125A depicts a detailed cross-sectional top plan view of a modifiedversion of the shaft assembly of FIG. 2 in a straight configuration withthe structural feature of FIG. 123 positioned thereabout in a distallongitudinal position;

FIG. 125B depicts a detailed cross-sectional top plan view of themodified shaft assembly of FIG. 125A in a straight configuration withthe structural feature of FIG. 123 positioned thereabout and moved intoa proximal longitudinal position;

FIG. 125C depicts a detailed cross-sectional top plan view of themodified shaft assembly of FIG. 125A in an articulated configurationwith the structural feature of FIG. 123 positioned thereabout in theproximal longitudinal position;

FIG. 126 depicts a perspective view of yet another exemplary structuralfeature that may be incorporated into the shaft assembly of FIG. 2;

FIG. 127 depicts a side view of the structural feature of FIG. 126;

FIG. 128 depicts a cross-sectional front view of the structural featureof FIG. 126, taken along line 128-128 of FIG. 127;

FIG. 129A depicts a detailed cross-sectional top plan view of a modifiedversion of the shaft assembly of FIG. 2 in a straight configuration withthe structural feature of FIG. 126 positioned thereabout in a distallongitudinal position;

FIG. 129B depicts a detailed cross-sectional top plan view of themodified shaft assembly of FIG. 129A in a straight configuration withthe structural feature of FIG. 126 positioned thereabout and moved intoa proximal longitudinal position;

FIG. 129C depicts a detailed cross-sectional top plan view of themodified shaft assembly of FIG. 129A in an articulated configurationwith the structural feature of FIG. 126 positioned thereabout in theproximal longitudinal position;

FIG. 130A depicts a detailed cross-sectional top plan view of themodified shaft assembly of FIG. 129A in a straight configuration with apair of the structural features of FIG. 126 positioned thereabout in adistal longitudinal position;

FIG. 130B depicts a detailed cross-sectional top plan view of themodified shaft assembly of FIG. 129A in a straight configuration with apair of the structural features of FIG. 126 positioned thereabout andmoved into a proximal longitudinal position;

FIG. 131 depicts a perspective view of yet another exemplary structuralfeature that may be incorporated into the shaft assembly of FIG. 2;

FIG. 132A depicts a detailed top plan view of the shaft assembly of FIG.2 with the structural feature of FIG. 131 spaced apart therefrom;

FIG. 132B depicts a detailed top plan view of the shaft assembly of FIG.2 with the structural feature of FIG. 131 positioned thereabout;

FIG. 133A depicts a detailed cross-sectional top plan view of a modifiedversion of the shaft assembly of FIG. 2 having a pair of exemplarystructural articulation bands in a straight configuration;

FIG. 133B depicts a detailed cross-sectional top plan view of themodified shaft assembly of FIG. 133A in an articulated configuration;

FIG. 134 depicts a side elevation view of an articulation band of themodified shaft assembly of FIG. 133A;

FIG. 135 depicts a side elevation view of another articulation band ofthe modified shaft assembly of FIG. 133A;

FIG. 136A depicts the articulation bands of FIG. 133A with “weak spots”of the articulation bands offset from one another;

FIG. 136B depicts the articulation bands of FIG. 133A with “weak spots”of the articulation bands aligned with one another;

FIG. 137 depicts a detailed cross-sectional top plan view of a modifiedversion of the shaft assembly of FIG. 2 having yet another exemplarystructural feature;

FIG. 138 depicts a detailed cross-sectional top plan view of a modifiedversion of the shaft assembly of FIG. 2 having yet another exemplarystructural feature;

FIG. 139 depicts a detailed cross-sectional top plan view of a modifiedversion of the shaft assembly of FIG. 2 having yet another exemplarystructural feature;

FIG. 140A depicts a detailed cross-sectional top plan view of a modifiedversion of the shaft assembly of FIG. 2 in a straight configurationhaving yet another exemplary structural feature;

FIG. 140B depicts a detailed cross-sectional top plan view of themodified shaft assembly of FIG. 140A in an articulated configuration;

FIG. 141 depicts a partially exploded perspective view of an exemplaryalternative articulation control assembly that may be incorporated intothe instrument of FIG. 1;

FIG. 142 depicts a side elevational view of a rotatable knob of thearticulation control assembly of FIG. 141;

FIG. 143 depicts a cross-sectional side view of the articulation controlassembly of FIG. 141, with the knob in a first position;

FIG. 144 depicts another side cross-sectional view of the articulationcontrol assembly of FIG. 141, with the knob in a second position;

FIG. 145 depicts a perspective view of another exemplary alternativearticulation control assembly that may be incorporated into theinstrument of FIG. 1;

FIG. 146 depicts a cross-sectional side view of the articulation controlassembly of FIG. 145, with the cross-section taken along line 146-146 ofFIG. 145, with a rotatable knob in a first position;

FIG. 147 depicts another cross-sectional side view of the articulationcontrol assembly of FIG. 145, with the cross-section taken along line146-146 of FIG. 145, with the rotatable knob pivoted to a secondposition;

FIG. 148 depicts a top plan view of an exemplary alternativearticulation section that may be incorporated into the instrument ofFIG. 1, with the articulation section in a straight configuration;

FIG. 149 depicts another top plan view of the articulation section ofFIG. 148, with the articulation section in an articulated configuration;

FIG. 150 depicts a top plan view of an exemplary alternative housingthat may be incorporated into the instrument of FIG. 1 for use with thearticulation section of FIG. 148;

FIG. 151 depicts a top cross-sectional view of another exemplaryalternative articulation section that may be incorporated into theinstrument of FIG. 1;

FIG. 152 depicts a side elevational view of an exemplary alternativeultrasonic surgical instrument;

FIG. 153 depicts a detailed side cut-away view of the instrument of FIG.152, with a tensioning assembly in a non-tensioning position;

FIG. 154 depicts a side cross-sectional view of a articulation controlassembly of the instrument of FIG. 152;

FIG. 155 depicts a detailed side cut-away view of the instrument of FIG.152, with a tensioning assembly in a tensioned position;

FIG. 156 depicts a side elevational view of another exemplaryalternative surgical instrument;

FIG. 157 depicts a detailed top plan view of a tensioning assembly ofthe instrument of FIG. 156;

FIG. 158 depicts a side cross-sectional view of a collar of thetensioning assembly of FIG. 157, with the cross-section taken along line158-158 of FIG. 157;

FIG. 159 depicts a detailed side elevational view of the tensioningassembly of FIG. 157, with the tensioning assembly in a non-tensioningposition;

FIG. 160 depicts another detailed side elevational view of thetensioning assembly of FIG. 157, with the tensioning assembly in atensioning position;

FIG. 161 depicts a top plan view of the shaft assembly and end effectorof FIG. 2, including a movable sheath, with the sheath in a proximalposition;

FIG. 162 depicts another top plan view of the shaft assembly and endeffector of FIG. 2, with the movable sheath of FIG. 161 advanced to adistal position;

FIG. 163 depicts a top plan view of the shaft assembly and end effectorof FIG. 2, including an exemplary alternative movable sheath, with thesheath in a first position;

FIG. 164 depicts another top plan view of the shaft assembly and endeffector of FIG. 2, with the movable sheath of FIG. 163 retracted to asecond position;

FIG. 165 depicts still another top plan view of the shaft assembly andend effector of FIG. 2, with the movable sheath of FIG. 163 advanced toa third position;

FIG. 166 depicts a perspective view of the articulation section of FIG.2, the articulation section including a rotatable sheath, with thesheath in a first angular position;

FIG. 167 depicts a front cross-sectional view of the rotatable sheath ofFIG. 166, the cross-section taken along line 167-167 of FIG. 166;

FIG. 168 depicts a top cross-sectional view of the articulation sectionand rotatable sheath of FIG. 166, the cross-section taken along line168-168 of FIG. 166;

FIG. 169 depicts another perspective view of the articulation section ofFIG. 2, with the rotatable sheath of FIG. 166 rotated to a secondangular position;

FIG. 170 depicts a top cross-sectional view of the articulation sectionand rotatable sheath of FIG. 166, with the cross-section taken alongline 170-170 of FIG. 169 and the sheath in the second angular position;

FIG. 171 depicts a perspective view of the articulation section of FIG.2, the articulation section including an exemplary alternative rotatablesheath, with the sheath in a first angular position;

FIG. 172 depicts another perspective view of the articulation sectionand rotatable sheath of FIG. 171, with the sheath rotated to a secondangular position;

FIG. 173 depicts a side elevational view of an exemplary alternativesheath assembly that may be incorporated into the instrument of FIG. 1,with an outer sheath in a first angular position;

FIG. 174 depicts a side cut-away view of the sheath assembly of FIG.173;

FIG. 175 depicts another side elevational view of the sheath assembly ofFIG. 173, with the outer sheath rotated to a second angular position;

FIG. 176 depicts a top plan view of the shaft assembly and end effectorof FIG. 2, including a coil sheath assembly, with the coil sheathassembly in a first position;

FIG. 177 depicts another top plan view of the shaft assembly and endeffector of FIG. 2, with the coil sheath assembly in a second position;

FIG. 178 depicts a top plan view of the shaft assembly and end effectorof FIG. 2, including a linkage assembly, with the linkage assembly in afirst configuration;

FIG. 179 depicts another top plan view of the shaft assembly and endeffector of FIG. 2, with the linkage assembly in a second configuration;

FIG. 180 depicts a top plan view of the shaft assembly and end effectorof FIG. 2, including a rigidizing plate assembly, with the rigidizingplate assembly in a proximal position;

FIG. 181 depicts a perspective view of the rigidizing member of therigidizing plate assembly of FIG. 180;

FIG. 182 depicts another top plan view of the shaft assembly and endeffector of FIG. 2, with the rigidizing plate assembly is a distalposition;

FIG. 183 depicts a side elevational view of an exemplary alternativesurgical instrument, with an outer sheath and actuation driver in aproximal position;

FIG. 184 depicts an exploded side view of the outer sheath and actuationdriver of FIG. 30;

FIG. 185 depicts a front end view of the actuation driver of FIG. 183;

FIG. 186 depicts another side elevational view of the instrument of FIG.183 with the outer sheath and actuation driver in a distal position;

FIG. 187 depicts a side elevational view of another exemplaryalternative surgical instrument, with a rigidizing member and a drivemember in a proximal position;

FIG. 188 depicts an exploded side view of the rigidizing member anddrive member of FIG. 187;

FIG. 189 depicts a front end view of the drive member of FIG. 187;

FIG. 190 depicts a front cross-sectional view of a shaft assembly of theinstrument of FIG. 187;

FIG. 191 depicts partial side elevational view of the instrument of FIG.187, with the drive member in the proximal position;

FIG. 192 depicts a detailed side elevational view of a shaft assemblyand end effector of the instrument of FIG. 187, with the rigidizingmember in the proximal position;

FIG. 193 depicts another partial side elevational view of the instrumentof FIG. 187, with the drive member in an intermediate position;

FIG. 194 depicts another detailed side elevational view of the shaftassembly and the end effector of the instrument of FIG. 187, with therigidizing member in an intermediate position;

FIG. 195 depicts still another partial side elevational view of theinstrument of FIG. 187, with the drive member in a distal position;

FIG. 196 depicts still another detailed side elevational view of theshaft assembly and the end effector of the instrument of FIG. 187, withthe rigidizing member in a distal position;

FIG. 197 depicts an exploded view of an exemplary alternative rigidizingmember and drive member that may be incorporated into the instrument ofFIG. 187;

FIG. 198 depicts an front end view of the drive member of FIG. 197;

FIG. 199 depicts a cross-sectional view of the shaft assembly of theinstrument of FIG. 34 incorporating the rigidizing member of FIG. 197;

FIG. 200 depicts a partial side elevational view of the instrument ofFIG. 187 incorporating the rigidizing member and drive member of FIG.197, with the drive member in a proximal position;

FIG. 201 depicts a detailed top plan view of a shaft assembly and endeffector of the instrument of FIG. 187 incorporating the rigidizingmember and drive member of FIG. 197, with the rigidizing member in aproximal position;

FIG. 202 depicts another partial side elevational view of the instrumentof FIG. 187 incorporating the rigidizing member and drive member of FIG.197, with the drive member in an intermediate position;

FIG. 203 depicts another detailed top plan view of the shaft assemblyand the end effector of the instrument of FIG. 187, with the rigidizingmember in an intermediate position;

FIG. 204 depicts still another partial side elevational view of theinstrument of FIG. 187 incorporating the rigidizing member and drivemember of FIG. 197, with the drive member in a distal position;

FIG. 205 depicts still another detailed top plan view of the shaftassembly and the end effector of the instrument of FIG. 187, with therigidizing member in a distal position;

FIG. 206 depicts a perspective view of an exemplary alternativewaveguide, including a curved blade;

FIG. 207 depicts a perspective view of a distal end of the waveguide ofFIG. 206;

FIG. 208 depicts a top view of the distal end of the waveguide of FIG.206, showing a bend angle of a blade of the waveguide;

FIG. 209 depicts a perspective view of an exemplary alternativearticulation section of a shaft assembly and an end effectorincorporating the waveguide of FIG. 206, which is suitable forincorporation into the surgical instrument of FIG. 1;

FIG. 210 depicts a perspective view of the articulation section of theshaft assembly and the end effector of FIG. 209, with certain partsomitted to show details;

FIG. 211 depicts an exploded perspective view of the articulationsection of the shaft assembly and the end effector of FIG. 209;

FIG. 212 depicts a perspective view of a distal flex member of thearticulation section of FIG. 209;

FIG. 213 depicts a cross-sectional view of the distal flex member ofFIG. 212, with the cross section taken along line 213-213 of FIG. 212;

FIG. 214 depicts a perspective view of a proximal flex member of thearticulation section of FIG. 209;

FIG. 215 depicts a front elevational view of the proximal flex member ofFIG. 214;

FIG. 216 depicts a perspective view of a plurality of flex base membersof the articulation section of FIG. 209, in an unflexed configuration;

FIG. 217 depicts a front elevational view of the plurality of flex basemembers of FIG. 216;

FIG. 218A depicts a top elevational view of the plurality of flex basemembers of FIG. 216, in an unflexed configuration;

FIG. 218B depicts a top elevational view of the flex base members ofFIG. 216, in a flexed configuration;

FIG. 219 depicts a perspective view of a distal tube member of thearticulation section of FIG. 14;

FIG. 220 depicts a top elevational view of the distal tube member ofFIG. 219;

FIG. 221 depicts a perspective view of a proximal tube member of thearticulation section of FIG. 209;

FIG. 222 depicts a top elevational view of the proximal tube member ofFIG. 221;

FIG. 223 depicts a perspective view of a plurality of flex rings of thearticulation section of FIG. 209 in an unflexed configuration;

FIG. 224A depicts a top elevational view of the plurality of flex ringsof FIG. 223, in an unflexed configuration;

FIG. 224B depicts a top elevational view of the set of flex rings ofFIG. 223, in a flexed configuration;

FIG. 225 depicts a perspective view of a collar of the articulationsection of FIG. 209;

FIG. 226 depicts a front elevational view of the collar of FIG. 225;

FIG. 227A depicts a top elevational view of the articulation section ofthe shaft assembly and the end effector of FIG. 209, showing thearticulation section in an unarticulated configuration;

FIG. 227B depicts a top elevational view of the articulation section ofthe shaft assembly and the end effector of FIG. 209, showing thearticulation section in an articulated configuration;

FIG. 228A depicts a top cross-sectional view of the articulation sectionof the shaft assembly and the end effector of FIG. 209, showing thearticulation section in an unarticulated configuration;

FIG. 228B depicts a top cross-sectional view of the articulation sectionof the shaft assembly and the end effector of FIG. 209, showing thearticulation section in an articulated configuration;

FIG. 229 depicts a side elevational view of another exemplary ultrasonicsurgical instrument;

FIG. 230 depicts a perspective view of the instrument of FIG. 229;

FIG. 231 depicts a side elevational view of a proximal portion of theinstrument of FIG. 229 with a shrouding half removed;

FIG. 232 depicts a detailed side elevational view of the instrument ofFIG. 229 with a shrouding half removed;

FIG. 233 depicts a cross-sectional front view of a shaft assembly of theinstrument of FIG. 229;

FIG. 234 depicts a perspective view of internal components of the shaftassembly of FIG. 233;

FIG. 235 depicts a partially exploded perspective view of anarticulation control assembly of the instrument of FIG. 229;

FIG. 236 depicts an exploded perspective view of a drive assembly of thearticulation control assembly of FIG. 235;

FIG. 237 depicts another partially exploded perspective view of thedrive assembly of FIG. 236;

FIG. 238 depicts a perspective view of a lead screw of the driveassembly of FIG. 236;

FIG. 239 depicts a front elevational view of the lead screw of FIG. 238;

FIG. 240 depicts a perspective view of another lead screw of the driveassembly of FIG. 236;

FIG. 241 depicts a front elevational view of the lead screw of FIG. 240;

FIG. 242A depicts a perspective view of a cylindrical guide of the driveassembly of FIG. 236;

FIG. 242B depicts a partially exploded perspective view of thecylindrical guide of FIG. 242A;

FIG. 243 depicts a cross-sectional perspective view of the driveassembly of FIG. 236, taken along the line 243-243 of FIG. 237;

FIG. 244 depicts a cross-sectional perspective view of the driveassembly of FIG. 236, taken along the line 244-244 of FIG. 237;

FIG. 245A depicts a detailed side elevational view of the instrument ofFIG. 229 with a shrouding half removed, and a cross-sectional top viewof an articulation section of the shaft assembly of FIG. 233, with thearticulation section in a substantially straight configuration;

FIG. 245B depicts a detailed side elevational view of the instrument ofFIG. 229 with a shrouding half removed, and a cross-sectional top viewof the articulation section of FIG. 245A, with the articulation sectionin a first stage of articulation;

FIG. 245C depicts a detailed side elevational view of the instrument ofFIG. 229 with a shrouding half removed, and a cross-sectional top viewof the articulation section of FIG. 245A, with the articulation sectionin a second stage of articulation;

FIG. 246 depicts a side elevational view of yet another exemplaryultrasonic surgical instrument;

FIG. 247 depicts a perspective view of the instrument of FIG. 246;

FIG. 248 depicts a perspective view of the instrument of FIG. 246, witha disposable portion separated from a reusable portion;

FIG. 249 depicts a perspective view of an exemplary alternativedisposable portion that may be used with the reusable portion of theinstrument of FIG. 246;

FIG. 250 depicts another perspective view the disposable portion of FIG.249;

FIG. 251 depicts a cross-sectional front view of a shaft assembly of thedisposable portion of FIG. 249, taken along line 251-251 of FIG. 249;

FIG. 252 depicts another cross-sectional front view of a shaft assemblyof the disposable portion of FIG. 249, taken along line 252-252 of FIG.249;

FIG. 253 depicts a perspective view of internal components of the shaftassembly of FIG. 252;

FIG. 254 depicts a side elevational view of a body portion of thedisposable portion of FIG. 249;

FIG. 255 depicts a side elevational view of the body portion of FIG. 254with a shrouding half removed;

FIG. 256 depicts a detailed side elevational view of the body portion ofFIG. 254 with a shrouding half removed;

FIG. 257 depicts a side elevational view of an articulation controlassembly of the disposable portion of FIG. 249;

FIG. 258 depicts a perspective view of the articulation control assemblyof FIG. 257;

FIG. 259A depicts a partially exploded side elevational view of thearticulation control assembly of FIG. 257;

FIG. 259B depicts a perspective view of a gear reduction assembly of thearticulation control assembly of FIG. 257;

FIG. 259C depicts an exploded perspective view of the gear reductionassembly of FIG. 259B;

FIG. 259D depicts a perspective view of a bevel gear of the gearreduction assembly of FIG. 259B;

FIG. 259E depicts a front elevational view of the bevel gear of FIG.259D;

FIG. 259F depicts a perspective view of a fixed spline member of thegear reduction assembly of FIG. 259B;

FIG. 259G depicts a rear elevational view of the fixed spline member ofFIG. 259F;

FIG. 259H depicts a perspective view of a flex spline member of the gearreduction assembly of FIG. 259B;

FIG. 259I depicts a rear elevational view of the flex spline member ofFIG. 259H;

FIG. 259J depicts a cross-sectional view of the gear reduction assemblyof FIG. 259B, taken along line 259J-259J of FIG. 259B;

FIG. 260 depicts a partial cross-sectional perspective view of a driveassembly of the articulation control assembly of FIG. 257;

FIG. 261 depicts a perspective view of a cylindrical guide of the driveassembly of FIG. 260;

FIG. 262 depicts a perspective view of a proximal rotatable housing ofthe drive assembly of FIG. 260;

FIG. 263 depicts a front elevational view of the proximal rotatablehousing of FIG. 262;

FIG. 264 depicts a cross-sectional side view of the proximal rotatablehousing of FIG. 262;

FIG. 265 depicts another cross-sectional side view of the proximalrotatable housing of FIG. 262;

FIG. 266 depicts a perspective view of a lead screw of the driveassembly of FIG. 260;

FIG. 267 depicts a front elevational view of the lead screw of FIG. 266;

FIG. 268 depicts a side elevational view of the lead screw of FIG. 266;

FIG. 269 depicts a perspective view of a translatable assembly of thedrive assembly of FIG. 260;

FIG. 270 depicts a cross-sectional perspective view of the translatableassembly of FIG. 269, taken along line 270-270 of FIG. 269;

FIG. 271 depicts a cross-sectional rear view of the drive assembly ofFIG. 260;

FIG. 272 depicts a perspective view of a distal rotatable housing of thedrive assembly of FIG. 260;

FIG. 273 depicts a side elevational view of the distal rotatable housingof FIG. 272;

FIG. 274 depicts a front elevational view of the distal rotatablehousing of FIG. 272;

FIG. 275 depicts a cross-sectional side view of the distal rotatablehousing of FIG. 272, taken along line 275-275 of FIG. 272;

FIG. 276 depicts another cross-sectional side view of the secondrotatable housing of FIG. 272, taken along line 276-276 of FIG. 272;

FIG. 277 depicts a perspective view of another lead screw of the driveassembly of FIG. 260;

FIG. 278 depicts a front elevational view of the lead screw of FIG. 277;

FIG. 279 depicts a bottom plan view of the lead screw of FIG. 277;

FIG. 280 depicts a perspective view of yet another lead screw of thedrive assembly of FIG. 260;

FIG. 281 depicts a front elevational view of the lead screw of FIG. 280;

FIG. 282 depicts a side elevational view of the lead screw of FIG. 280;

FIG. 283 depicts a perspective view of a tensioner of the drive assemblyof FIG. 260;

FIG. 284 depicts a side elevational view of the tensioner of FIG. 283;

FIG. 285 depicts a front elevational view of the tensioner of FIG. 283;

FIG. 286 depicts an exploded perspective view of the tensioner of FIG.283;

FIG. 287 depicts a top plan view of a proximal end of a pair oftranslatable rods of the shaft assembly of FIG. 252;

FIG. 288 depicts another cross-sectional rear view of the drive assemblyof FIG. 260;

FIG. 289 depicts yet another cross-sectional rear view of the driveassembly of FIG. 260;

FIG. 290 depicts yet another cross-sectional rear view of the driveassembly of FIG. 260;

FIG. 291A depicts a partial cross-sectional side view of the driveassembly of FIG. 260, with the lead screw of FIG. 266 in a firstlongitudinal position, with the lead screw of FIG. 277 in a firstlongitudinal position, and with the lead screw of FIG. 280 in a firstlongitudinal position;

FIG. 291B depicts a partial cross-sectional side view of the driveassembly of FIG. 260, with the lead screw of FIG. 266 moved to a secondlongitudinal position, with the lead screw of FIG. 277 moved to a secondlongitudinal position, and with the lead screw of FIG. 280 moved to asecond longitudinal position;

FIG. 291C depicts a partial cross-sectional side view of the driveassembly of FIG. 260, with the lead screw of FIG. 266 moved to a thirdlongitudinal position, with the lead screw of FIG. 277 moved to a thirdlongitudinal position, and with the lead screw of FIG. 280 moved to athird longitudinal position;

FIG. 292A depicts a cross-sectional perspective view of the shaftassembly of FIG. 252, with a rod member in a first longitudinalposition;

FIG. 292B depicts a cross-sectional perspective view of the shaftassembly of FIG. 252, with the rod member of FIG. 292A moved to a secondlongitudinal position;

FIG. 293A depicts a cross-sectional top view of the shaft assembly ofFIG. 252, with an articulation section of the shaft assembly in astraight configuration;

FIG. 293B depicts a cross-sectional top view of the shaft assembly ofFIG. 252, with the articulation section of FIG. 293B moved to a firstarticulated configuration;

FIG. 293C depicts a cross-sectional top view of the shaft assembly ofFIG. 252, with the articulation section of FIG. 293B moved to a secondarticulated configuration;

FIG. 294 depicts a perspective view of a stiffening assembly that may beused with the ultrasonic surgical instruments of FIGS. 229 and 246;

FIG. 295 depicts a detailed perspective view of a proximal end of atubular member of the stiffening assembly of FIG. 294;

FIG. 296 depicts a detailed perspective view of a tubular guide of thestiffening assembly of FIG. 294;

FIG. 297A depicts a detailed side elevational view of the tubular memberof FIG. 295 coupled with the tubular guide of FIG. 296, with the tubularmember in a first longitudinal position, and with the tubular guide in afirst rotational position;

FIG. 297B depicts a detailed side elevational view of the tubular memberof FIG. 295 coupled with the tubular guide of FIG. 296, with the tubularmember moved to a second longitudinal position by rotation of thetubular guide to a second rotational position;

FIG. 297C depicts a detailed side elevational view of the tubular memberof FIG. 295 coupled with the tubular guide of FIG. 296, with the tubularmember moved to a third longitudinal position by rotation of the tubularguide to a third rotational position;

FIG. 298A depicts a detailed side elevational view of the tubular memberof FIG. 295 in the first longitudinal position relative to anarticulation section;

FIG. 298B depicts a detailed side elevational view of the tubular memberof FIG. 295 moved to the second longitudinal position relative to thearticulation section of FIG. 298A; and

FIG. 298C depicts a detailed side elevational view of the tubular memberof FIG. 295 moved to the third longitudinal position relative to thearticulation section of FIG. 298A.

The drawings are not intended to be limiting in any way, and it iscontemplated that various embodiments of the technology may be carriedout in a variety of other ways, including those not necessarily depictedin the drawings. The accompanying drawings incorporated in and forming apart of the specification illustrate several aspects of the presenttechnology, and together with the description serve to explain theprinciples of the technology; it being understood, however, that thistechnology is not limited to the precise arrangements shown.

DETAILED DESCRIPTION

The following description of certain examples of the technology shouldnot be used to limit its scope. Other examples, features, aspects,embodiments, and advantages of the technology will become apparent tothose skilled in the art from the following description, which is by wayof illustration, one of the best modes contemplated for carrying out thetechnology. As will be realized, the technology described herein iscapable of other different and obvious aspects, all without departingfrom the technology. Accordingly, the drawings and descriptions shouldbe regarded as illustrative in nature and not restrictive.

It is further understood that any one or more of the teachings,expressions, embodiments, examples, etc. described herein may becombined with any one or more of the other teachings, expressions,embodiments, examples, etc. that are described herein. Thefollowing-described teachings, expressions, embodiments, examples, etc.should therefore not be viewed in isolation relative to each other.Various suitable ways in which the teachings herein may be combined willbe readily apparent to those of ordinary skill in the art in view of theteachings herein. Such modifications and variations are intended to beincluded within the scope of the claims.

For clarity of disclosure, the terms “proximal” and “distal” are definedherein relative to a human or robotic operator of the surgicalinstrument. The term “proximal” refers the position of an element closerto the human or robotic operator of the surgical instrument and furtheraway from the surgical end effector of the surgical instrument. The term“distal” refers to the position of an element closer to the surgical endeffector of the surgical instrument and further away from the human orrobotic operator of the surgical instrument.

I. EXEMPLARY ULTRASONIC SURGICAL INSTRUMENT

FIG. 1 shows an exemplary ultrasonic surgical instrument (10). At leastpart of instrument (10) may be constructed and operable in accordancewith at least some of the teachings of any of the various patents,patent application publications, and patent applications that are citedherein. As described therein and as will be described in greater detailbelow, instrument (10) is operable to cut tissue and seal or weld tissue(e.g., a blood vessel, etc.) substantially simultaneously. It shouldalso be understood that instrument (10) may have various structural andfunctional similarities with the HARMONIC ACE® Ultrasonic Shears, theHARMONIC WAVE® Ultrasonic Shears, the HARMONIC FOCUS® Ultrasonic Shears,and/or the HARMONIC SYNERGY® Ultrasonic Blades. Furthermore, instrument(10) may have various structural and functional similarities with thedevices taught in any of the other references that are cited andincorporated by reference herein.

To the extent that there is some degree of overlap between the teachingsof the references cited herein, the HARMONIC ACE® Ultrasonic Shears, theHARMONIC WAVE® Ultrasonic Shears, the HARMONIC FOCUS® Ultrasonic Shears,and/or the HARMONIC SYNERGY® Ultrasonic Blades, and the followingteachings relating to instrument (10), there is no intent for any of thedescription herein to be presumed as admitted prior art. Severalteachings herein will in fact go beyond the scope of the teachings ofthe references cited herein and the HARMONIC ACE® Ultrasonic Shears, theHARMONIC WAVE® Ultrasonic Shears, the HARMONIC FOCUS® Ultrasonic Shears,and the HARMONIC SYNERGY® Ultrasonic Blades.

Instrument (10) of the present example comprises a handle assembly (20),a shaft assembly (30), and an end effector (40). Handle assembly (20)comprises a body (22) including a pistol grip (24) and a pair of buttons(26). Handle assembly (20) also includes a trigger (28) that ispivotable toward and away from pistol grip (24). It should beunderstood, however, that various other suitable configurations may beused, including but not limited to a scissor grip configuration. Endeffector (40) includes an ultrasonic blade (160) and a pivoting clamparm (44). Clamp arm (44) is coupled with trigger (28) such that clamparm (44) is pivotable toward ultrasonic blade (160) in response topivoting of trigger (28) toward pistol grip (24); and such that clamparm (44) is pivotable away from ultrasonic blade (160) in response topivoting of trigger (28) away from pistol grip (24). Various suitableways in which clamp arm (44) may be coupled with trigger (28) will beapparent to those of ordinary skill in the art in view of the teachingsherein. In some versions, one or more resilient members are used to biasclamp arm (44) and/or trigger (28) to the open position shown in FIG. 1.

An ultrasonic transducer assembly (12) extends proximally from body (22)of handle assembly (20). Transducer assembly (12) is coupled with agenerator (16) via a cable (14), such that transducer assembly (12)receives electrical power from generator (16). Piezoelectric elements intransducer assembly (12) convert that electrical power into ultrasonicvibrations. Generator (16) may include a power source and control modulethat is configured to provide a power profile to transducer assembly(12) that is particularly suited for the generation of ultrasonicvibrations through transducer assembly (12). By way of example only,generator (16) may comprise a GEN 300 sold by Ethicon Endo-Surgery, Inc.of Cincinnati, Ohio. In addition or in the alternative, generator (16)may be constructed in accordance with at least some of the teachings ofU.S. Pat. No. 8,986,302, entitled “Surgical Generator for Ultrasonic andElectrosurgical Devices,” published Apr. 14, 2011, the disclosure ofwhich is incorporated by reference herein. It should also be understoodthat at least some of the functionality of generator (16) may beintegrated into handle assembly (20), and that handle assembly (20) mayeven include a battery or other on-board power source such that cable(14) is omitted. Still other suitable forms that generator (16) maytake, as well as various features and operabilities that generator (16)may provide, will be apparent to those of ordinary skill in the art inview of the teachings herein.

A. Exemplary End Effector and Acoustic Drivetrain

As best seen in FIGS. 2-4, end effector (40) of the present examplecomprises clamp arm (44) and ultrasonic blade (160). Clamp arm (44)includes a clamp pad (46) that is secured to the underside of clamp arm(44), facing blade (160). Clamp pad (46) may comprisepolytetrafluoroethylene (PTFE) and/or any other suitable material(s).Clamp arm (44) is pivotally secured to a distally projecting tongue (43)of an upper distal shaft element (172), which is fixedly secured withina distal portion of a distal outer sheath (33). Clamp arm (44) isoperable to selectively pivot toward and away from blade (160) toselectively clamp tissue between clamp arm (44) and blade (160). A pairof arms (156) extend transversely from clamp arm (44) and are pivotallysecured to a lower distal shaft element (170), which is slidablydisposed within the distal portion of distal outer sheath (33).

As best seen in FIGS. 7-8, a cable (174) is secured to lower distalshaft element (170). Cable (174) is operable to translate longitudinallyrelative to an articulation section (130) of shaft assembly (30) toselectively pivot clamp arm (44) toward and away from blade (160). Inparticular, cable (174) is coupled with trigger (28) such that cable(174) translates proximally in response to pivoting of trigger (28)toward pistol grip (24), and such that clamp arm (44) thereby pivotstoward blade (160) in response to pivoting of trigger (28) toward pistolgrip (24). In addition, cable (174) translates distally in response topivoting of trigger (28) away from pistol grip (24), such that clamp arm(44) pivots away from blade (160) in response to pivoting of trigger(28) away from pistol grip (24). Clamp arm (44) may be biased toward theopen position, such that (at least in some instances) the operator mayeffectively open clamp arm (44) by releasing a grip on trigger (28).

As shown in FIGS. 7-8, cable (174) is secured to a proximal end of lowerdistal shaft element (170). Lower distal shaft element (170) comprises apair of distal flanges (171, 173) extending from a semi-circular base(168). Flanges (171, 173) each comprise a respective opening (175, 177).Clamp arm (44) is rotatably coupled to lower distal shaft element (170)via a pair of inwardly extending integral pins (41, 45). Pins (41, 45)extend inwardly from arms (156) of clamp arm (44) and are rotatablydisposed within respective openings (175, 177) of lower distal shaftelement (170). As shown in FIGS. 10A-10C, longitudinal translation ofcable (174) causes longitudinal translation of lower distal shaftelement (170) between a proximal position (FIG. 10A) and a distalposition (FIG. 10C). Longitudinal translation of lower distal shaftelement (170) causes rotation of clamp arm (44) between a closedposition (FIG. 10A) and an open position (FIG. 10C).

Blade (160) of the present example is operable to vibrate at ultrasonicfrequencies in order to effectively cut through and seal tissue,particularly when the tissue is being compressed between clamp pad (46)and blade (160). Blade (160) is positioned at the distal end of anacoustic drivetrain. This acoustic drivetrain includes transducerassembly (12) and an acoustic waveguide (180). Acoustic waveguide (180)comprises a flexible portion (166). Transducer assembly (12) includes aset of piezoelectric discs (not shown) located proximal to a horn (notshown) of waveguide (180). The piezoelectric discs are operable toconvert electrical power into ultrasonic vibrations, which are thentransmitted along waveguide (180), including flexible portion (166) ofwaveguide (180) to blade (160) in accordance with known configurationsand techniques. By way of example only, this portion of the acousticdrivetrain may be configured in accordance with various teachings ofvarious references that are cited herein.

As best seen in FIG. 3, flexible portion (166) of waveguide (180)includes a distal flange (136), a proximal flange (138), and a narrowedsection (164) located between flanges (136, 138). In the presentexample, flanges (136, 138) are located at positions corresponding tonodes associated with resonant ultrasonic vibrations communicatedthrough flexible portion (166) of waveguide (180). Narrowed section(164) is configured to allow flexible portion (166) of waveguide (180)to flex without significantly affecting the ability of flexible portion(166) of waveguide (180) to transmit ultrasonic vibrations. By way ofexample only, narrowed section (164) may be configured in accordancewith one or more teachings of U.S. Pub. No. 2014/0005701, issued as U.S.Pat. No. 9,393,037 on Jul. 19, 2016, and/or U.S. Pub. No. 2014/0114334,issued as U.S. Pat. No. 9,095,367 on Aug. 4, 2015, the disclosures ofwhich are incorporated by reference herein. It should be understood thatwaveguide (180) may be configured to amplify mechanical vibrationstransmitted through waveguide (180). Furthermore, waveguide (180) mayinclude features operable to control the gain of the longitudinalvibrations along waveguide (180) and/or features to tune waveguide (180)to the resonant frequency of the system. Various suitable ways in whichwaveguide (180) may be mechanically and acoustically coupled withtransducer assembly (12) will be apparent to those of ordinary skill inthe art in view of the teachings herein.

In the present example, the distal end of blade (160) is located at aposition corresponding to an anti-node associated with resonantultrasonic vibrations communicated through flexible portion (166) ofwaveguide (180), in order to tune the acoustic assembly to a preferredresonant frequency f_(o) when the acoustic assembly is not loaded bytissue. When transducer assembly (12) is energized, the distal end ofblade (160) is configured to move longitudinally in the range of, forexample, approximately 10 to 500 microns peak-to-peak, and in someinstances in the range of about 20 to about 200 microns at apredetermined vibratory frequency f_(o) of, for example, 55.5 kHz. Whentransducer assembly (12) of the present example is activated, thesemechanical oscillations are transmitted through waveguide (180) to reachblade (160), thereby providing oscillation of blade (160) at theresonant ultrasonic frequency. Thus, when tissue is secured betweenblade (160) and clamp pad (46), the ultrasonic oscillation of blade(160) may simultaneously sever the tissue and denature the proteins inadjacent tissue cells, thereby providing a coagulative effect withrelatively little thermal spread. In some versions, an electricalcurrent may also be provided through blade (160) and clamp arm (44) toalso cauterize the tissue. While some configurations for an acoustictransmission assembly and transducer assembly (12) have been described,still other suitable configurations for an acoustic transmissionassembly and transducer assembly (12) will be apparent to one orordinary skill in the art in view of the teachings herein. Similarly,other suitable configurations for end effector (40) will be apparent tothose of ordinary skill in the art in view of the teachings herein.

B. Exemplary Shaft Assembly and Articulation Section

Shaft assembly (30) of the present example extends distally from handleassembly (20). As shown in FIGS. 2-7, shaft assembly (30) includesdistal outer sheath (33) and a proximal outer sheath (32) that encloseclamp arm (44) drive features and the above-described acoustictransmission features. Shaft assembly (30) further includes anarticulation section (130), which is located at a distal portion ofshaft assembly (30), with end effector (40) being located distal toarticulation section (130). As shown in FIG. 1, a knob (31) is securedto a proximal portion of proximal outer sheath (32). Knob (31) isrotatable relative to body (22), such that shaft assembly (30) isrotatable about the longitudinal axis defined by outer sheath (32),relative to handle assembly (20). Such rotation may provide rotation ofend effector (40), articulation section (130), and shaft assembly (30)unitarily. Of course, rotatable features may simply be omitted ifdesired.

Articulation section (130) is operable to selectively position endeffector (40) at various lateral deflection angles relative to alongitudinal axis defined by outer sheath (32). Articulation section(130) may take a variety of forms. By way of example only, articulationsection (130) may be configured in accordance with one or more teachingsof U.S. Pub. No. 2012/0078247, now issued as U.S. Pat. No. 9,402,682 onAug. 2, 2016, the disclosure of which is incorporated by referenceherein. As another merely illustrative example, articulation section(130) may be configured in accordance with one or more teachings of U.S.Pub. No. 2014/0005701, now issued as U.S. Pat. No. 9,393,037 on Jul. 19,2016, and/or U.S. Pub. No. 2014/0114334, now issued as U.S. Pat. No.9,095,367 on Aug. 4, 2015, the disclosures of which are incorporated byreference herein. Various other suitable forms that articulation section(130) may take will be apparent to those of ordinary skill in the art inview of the teachings herein.

As best seen in FIGS. 2-6B articulation section (130) of this examplecomprises a set of three retention collars (133) and a pair of ribbedbody portions (132, 134), with a pair of articulation bands (140, 142)extending along respective channels (135, 137) defined between interiorsurfaces of retention collars (133) and exterior surfaces of ribbed bodyportions (132, 134). Ribbed body portions (132, 134) are longitudinallypositioned between flanges (136, 138) of flexible portion (166) ofwaveguide (180). In some versions, ribbed body portions (132, 134) snaptogether about flexible portion (166) of waveguide (180). Ribbed bodyportions (132, 134) are configured to flex with flexible portion (166)of waveguide (180) when articulation section (130) bends to achieve anarticulated state.

FIG. 3 shows ribbed body portions (132, 134) in greater detail. In thepresent example, ribbed body portions (132, 134) are formed of aflexible plastic material, though it should be understood that any othersuitable material may be used. Ribbed body portion (132) comprises a setof three ribs (150) that are configured to promote lateral flexing ofribbed body portion (132). Of course, any other suitable number of ribs(150) may be provided. Ribbed body portion (132) also defines a channel(135) that is configured to receive articulation band (140) whileallowing articulation band (140) to slide relative to ribbed bodyportion (132). Similarly, ribbed body portion (134) comprises a set ofthree ribs (152) that are configured to promote lateral flexing ofribbed body portion (134). Of course, any other suitable number of ribs(152) may be provided. Ribbed body portion (134) also defines a channel(137) that is configured to receive articulation band (142) whileallowing articulation band (142) to slide relative to ribbed bodyportion (137).

As best seen in FIG. 5, ribbed body portions (132, 134) are laterallyinterposed between articulation bands (140, 142) and flexible portion(166) of waveguide (180). Ribbed body portions (132, 134) mate with eachother such that they together define an internal passage sized toaccommodate flexible portion (166) of waveguide (180) without contactingwaveguide (180). In addition, when ribbed body portions (132, 134) arecoupled together, a pair of complementary distal notches (131A, 131B)formed in ribbed body portions (132, 134) align to receive a pair ofinwardly projecting resilient tabs (38) of distal outer sheath (33).This engagement between tabs (38) and notches (131A, 131B)longitudinally secures ribbed body portions (132, 134) relative todistal outer sheath (33). Similarly, when ribbed body portions (132,134) are coupled together, a pair of complementary proximal notches(139A, 139B) formed in ribbed body portions (132, 134) align to receivea pair of inwardly projecting resilient tabs (37) of proximal outersheath (32). This engagement between tabs (37) and notches (139A, 139B)longitudinally secures ribbed body portions (132, 134) relative toproximal outer sheath (32). Of course, any other suitable kinds offeatures may be used to couple ribbed body portions (132, 134) withproximal outer sheath (32) and/or distal outer sheath (33).

The distal ends of articulation bands (140, 142) are unitarily securedto upper distal shaft element (172). When articulation bands (140, 142)translate longitudinally in an opposing fashion, this will causearticulation section (130) to bend, thereby laterally deflecting endeffector (40) away from the longitudinal axis of shaft assembly (30)from a straight configuration as shown in FIG. 6A to an articulatedconfiguration as shown in FIG. 6B. In particular, end effector (40) willbe articulated toward the articulation band (140, 142) that is beingpulled proximally. During such articulation, the other articulation band(140, 142) may be pulled distally by upper distal shaft element (172).Alternatively, the other articulation band (140, 142) may be drivendistally by an articulation control. Ribbed body portions (132, 134) andnarrowed section (164) are all sufficiently flexible to accommodate theabove-described articulation of end effector (40). Furthermore, flexibleacoustic waveguide (166) is configured to effectively communicateultrasonic vibrations from waveguide (180) to blade (160) even whenarticulation section (130) is in an articulated state as shown in FIG.6B.

As best seen in FIG. 3, each flange (136, 138) of waveguide (180)includes a respective pair of opposing flats (192, 196). Flats (192,196) are oriented along vertical planes that are parallel to a verticalplane extending through narrowed section (164) of flexible portion(166). Flats (192, 196) are configured to provide clearance forarticulation bands (140, 142). In particular, flats (196) of proximalflange (138) accommodate articulation bands (140, 142) between proximalflange (138) and the inner diameter of proximal outer sheath (32): whileflats (192) of distal flange (136) accommodate articulation bands (140,142) between distal flange (136) and the inner diameter of distal outersheath (33). Of course, flats (192, 196) could be substituted with avariety of features, including but not limited to slots, channels, etc.,with any suitable kind of profile (e.g., square, flat, round, etc.). Inthe present example, flats (192, 196) are formed in a milling process,though it should be understood that any other suitable process(es) maybe used. Various suitable alternative configurations and methods offorming flats (192, 196) will be apparent to those of ordinary skill inthe art in view of the teachings herein. It should also be understoodthat waveguide (180) may include flats formed in accordance with atleast some of the teachings of U.S. Pub. No. 2013/0289592, entitled“Ultrasonic Device for Cutting and Coagulating,” published Oct. 31,2013, the disclosure of which is incorporated by reference herein.

In the present example, outer rings (133) are located at longitudinalpositions corresponding to ribs (150, 152), such that three rings (133)are provided for three ribs (150, 152). Articulation band (140) islaterally interposed within channel (135) between rings (133) and ribbedbody portion (132); while articulation band (142) is laterallyinterposed within channel (137) between rings (133) and ribbed bodyportion (134). Rings (133) are configured to keep articulation bands(140, 142) in a parallel relationship, particularly when articulationsection (130) is in a bent configuration (e.g., similar to theconfiguration shown in FIG. 6B). In other words, when articulation band(140) is on the inner diameter of a curved configuration presented by abent articulation section (130), rings (133) may retain articulationband (140) such that articulation band (140) follows a curved path thatcomplements the curved path followed by articulation band (142). Itshould be understood that channels (135, 137) are sized to accommodaterespective articulation bands (140, 142) in such a way that articulationbands (140, 142) may still freely slide through articulation section(130), even with rings (133) being secured to ribbed body portions (150,152). It should also be understood that rings (133) may be secured toribbed body portions (132, 134) in various ways, including but notlimited to interference fitting, adhesives, welding, etc.

When articulation bands (140, 142) are translated longitudinally in anopposing fashion, a moment is created and applied to a distal end ofdistal outer sheath (33) via upper distal shaft element (172). Thiscauses articulation section (130) and narrowed section (164) of flexibleportion (166) of waveguide (180) to articulate, without transferringaxial forces in articulation bands (140, 142) to waveguide (180). Itshould be understood that one articulation band (140, 142) may beactively driven distally while the other articulation band (140, 142) ispassively permitted to retract proximally. As another merelyillustrative example, one articulation band (140, 142) may be activelydriven proximally while the other articulation band (140, 142) ispassively permitted to advance distally. As yet another merelyillustrative example, one articulation band (140, 142) may be activelydriven distally while the other articulation band (140, 142) is activelydriven proximally. Various suitable ways in which articulation bands(140, 142) may be driven will be apparent to those of ordinary skill inthe art in view of the teachings herein.

As best seen in FIG. 9, an articulation control assembly (100) issecured to a proximal portion of outer sheath (32). Articulation controlassembly (100) comprises a housing (110) and a rotatable knob (120).Housing (110) comprises a pair of perpendicularly intersectingcylindrical portions (112, 114). Knob (120) is rotatably disposed withina first hollow cylindrical portion (112) of housing (110) such that knob(120) is operable to rotate within cylindrical portion (112) of housing(110). Shaft assembly (30) is slidably and rotatably disposed within asecond cylindrical portion (114). Shaft assembly (30) comprises a pairof translatable members (161, 162), both of which extend slidably andlongitudinally through the proximal portion of outer sheath (32).Translatable members (161, 162) are longitudinally translatable withinsecond cylindrical portion (114) between a distal position and aproximal position. Translatable members (161, 162) are mechanicallycoupled with respective articulation bands (140, 142) such thatlongitudinal translation of translatable member (161) causeslongitudinal translation of articulation band (140), and such thatlongitudinal translation of translatable member (162) causeslongitudinal translation of articulation band (142).

Knob (120) comprises a pair of pins (122, 124) extending downwardly froma bottom surface of knob (120). Pins (122, 124) extend into secondcylindrical portion (114) of housing (110) and are rotatably andslidably disposed within a respective pair of channels (163, 164) formedin top surfaces of translatable members (161, 162). Channels (163, 164)are positioned on opposite sides of an axis of rotation of knob (120),such that rotation of knob (120) about that axis causes opposinglongitudinal translation of translatable members (161, 162). Forinstance, rotation of knob (120) in a first direction causes distallongitudinal translation of translatable member (161) and articulationband (140), and proximal longitudinal translation of translatable member(162) and articulation band (142); and rotation of knob (120) in asecond direction causes proximal longitudinal translation oftranslatable member (161) and articulation band (140), and distallongitudinal translation of translatable member (162) and articulationband (142). Thus, it should be understood that rotation of rotation knob(120) causes articulation of articulation section (130).

Housing (110) of articulation control assembly (100) comprises a pair ofset screws (111, 113) extending inwardly from an interior surface offirst cylindrical portion (112). With knob (120) rotatably disposedwithin first cylindrical portion (112) of housing (110), set screws(111, 113) are slidably disposed within a pair of arcuate channels (121,123) formed in knob (120). Thus, it should be understood that rotationof knob (120) will be limited by movement of set screws (111, 113)within channels (121, 123). Set screws (111, 113) also retain knob (120)in housing (110), preventing knob (120) from traveling vertically withinfirst cylindrical portion (112) of housing (110).

An interior surface of first cylindrical portion (112) of housing (110)comprises a first angular array of teeth (116) and a second angulararray of teeth (118) formed in an interior surface of first cylindricalportion (112). Rotation knob (120) comprises a pair of outwardlyextending engagement members (126, 128) that are configured to engageteeth (116, 118) of first cylindrical portion (112) in a detentrelationship to thereby selectively lock knob (120) in a particularrotational position. The engagement of engagement members (126, 128)with teeth (116, 118) may be overcome by a user applying sufficientrotational force to knob (120); but absent such force, the engagementwill suffice to maintain the straight or articulated configuration ofarticulation section (130). It should therefore be understood that theability to selectively lock knob (120) in a particular rotationalposition lock will enable an operator to selectively lock articulationsection (130) in a particular deflected position relative to thelongitudinal axis defined by outer sheath (32).

In some versions of instrument (10), articulation section (130) of shaftassembly (30) is operable to achieve articulation angles up to betweenapproximately 15° and approximately 30°, both relative to thelongitudinal axis of shaft assembly (30) when shaft assembly (30) is ina straight (non-articulated) configuration. Alternatively, articulationsection (130) may be operable to achieve any other suitable articulationangles.

In some versions of instrument (10), narrowed section (164) of waveguide(180) has a thickness between approximately 0.01 inches andapproximately 0.02 inches. Alternatively, narrowed section (164) mayhave any other suitable thickness. Also in some versions, narrowedsection (164) has a length of between approximately 0.4 inches andapproximately 0.65 inches. Alternatively, narrowed section (164) mayhave any other suitable length. It should also be understood that thetransition regions of waveguide (180) leading into and out of narrowedsection (164) may be quarter rounded, tapered, or have any othersuitable configuration.

In some versions of instrument (10), flanges (136, 138) each have alength between approximately 0.1 inches and approximately 0.2 inches.Alternatively, flanges (136, 138) may have any other suitable length. Itshould also be understood that the length of flange (136) may differfrom the length of flange (138). Also in some versions, flanges (136,138) each have a diameter between approximately 0.175 inches andapproximately 0.2 inches. Alternatively, flanges (136, 138) may have anyother suitable outer diameter. It should also be understood that theouter diameter of flange (136) may differ from the outer diameter offlange (138).

While the foregoing exemplary dimensions are provided in the context ofinstrument (10) as described above, it should be understood that thesame dimensions may be used in any of the other examples describedherein. It should also be understood that the foregoing exemplarydimensions are merely optional. Any other suitable dimensions may beused.

C. Exemplary Alternative End Effector and Shaft Assembly Configurationwith Dual Role Bands and Flex Section as Ground

FIGS. 11A-12B show an exemplary alternative shaft assembly (200) and endeffector (240) that may be readily incorporated into instrument (10).Shaft assembly (200) of this example comprises a distal outer sheath(202), a proximal outer sheath (204), and an articulation section (210)configured to operate substantially similar to articulation section(130) discussed above except for the differences discussed below. Inparticular, articulation section (210) is operable to selectivelyposition end effector (240) at various lateral deflection anglesrelative to a longitudinal axis defined by proximal outer sheath (204).End effector (240) includes an ultrasonic blade (242) and a pivotingclamp arm (244) having a clamp pad (245). End effector (240) isconfigured to operate substantially similar to end effector (40)discussed above except for the differences discussed below. Inparticular, clamp arm (244) of end effector (240) is operable tocompress tissue against blade (242). When blade (242) is activated whileclamp arm (244) compresses tissue against blade (242), end effector(240) simultaneously severs the tissue and denatures the proteins inadjacent tissue cells, thereby providing a coagulative effect.

Clamp arm (244) is operable to selectively pivot toward and away fromblade (242) to selectively clamp tissue between clamp pad (245) andblade (242). Clamp arm (244) is pivotably secured to an upper distal endof distal outer sheath (202) via a pin (222). Distal outer sheath (202)is mechanically grounded to an instrument body (e.g., handle assembly(20), etc.) via articulation section (210) and proximal outer sheath(204). A pair of arms (247) extend transversely from clamp arm (244) andare pivotably secured to a collar (220) via a pin (224). Collar (220) isslidably disposed within distal outer sheath (202). Thus, it should beunderstood that longitudinal movement of collar (220) within distalouter sheath (202) causes pivoting of clamp arm (244) about pin (222)toward and away from blade (242). Collar (220) is longitudinally drivenwithin distal outer sheath (202) as described in greater detail below.

Blade (242) is positioned at the distal end of an acoustic drivetrain,which passes through an inner bore of collar (220) without contactingcollar (220). This acoustic drivetrain includes a transducer assembly(not shown) and an acoustic waveguide (246). Waveguide (246) comprises aflexible portion (248). Flexible portion (248) of waveguide (246)includes a distal flange (250), a proximal flange (not shown), and anarrowed section (249) located between distal flange (250) and theproximal flange. In the present example, distal flange (250) and theproximal flange are located at positions corresponding to nodesassociated with resonant ultrasonic vibrations communicated throughflexible portion (248) of waveguide (246). Narrowed section (249) isconfigured to allow flexible portion (248) of waveguide (246) to flexwithout significantly affecting the ability of flexible portion (248) ofwaveguide (246) to transmit ultrasonic vibrations. As best seen in FIG.11A-11B, distal flange (250) engages an interior surface of distal outersheath (202). In some versions, a gap is defined between distal flange(250) and the interior surface of distal outer sheath (202). In someother versions, a dampening element such as an o-ring is interposedbetween distal flange (250) and the interior surface of distal outersheath (202).

Shaft assembly (200) further comprises a pair of articulation bands(212, 214). Distal ends of articulation bands (212, 214) are secured tocollar (220). Articulation bands (212, 214) are configured to operatesubstantially similar to articulation bands (140, 142) discussed aboveexcept for the differences discussed below. In particular, as shown inFIGS. 12A-12B, opposing longitudinal motion of articulation bands (212,214) causes articulation of articulation section (210). Whenarticulation bands (212, 214) are translated longitudinally in anopposing fashion, a moment is created and applied to a distal end ofdistal outer sheath (202) via pin (222), arms (247) of clamp arm (244),pin (224), and collar (220). This causes articulation section (210) andnarrowed section (249) of flexible portion (248) of waveguide (246) toarticulate, without transferring axial forces in articulation bands(212, 214) to waveguide (246).

As shown in FIGS. 11A-11B, when articulation bands (212, 214) are bothtranslated in the same direction simultaneously, this simultaneouslongitudinal movement of articulation bands (212, 214) causes concurrentlongitudinal movement of collar (220) relative to distal outer sheath(202) and the other grounded components of shaft assembly (200). Thus,the simultaneous longitudinal motion of articulation bands (212, 214) inthe same direction causes pivoting of clamp arm (244) toward and awayfrom ultrasonic blade (242). It should therefore be understood thatopposing longitudinal motion of articulation bands (212, 214) will causearticulation of articulation section (210); distal movement of botharticulation bands (212, 214) simultaneously will cause clamp arm (244)to pivot away from blade (242); and proximal movement of botharticulation bands (212, 214) simultaneously will cause clamp arm (244)to pivot toward blade (242).

Articulation bands (212, 214) may be driven to translate in an opposingfashion by a modified version of articulation control assembly (100).Articulation bands (212, 214) may be driven to translate in the samedirection simultaneously by a modified version of trigger (28). Forinstance, pivoting of trigger (28) toward and away from pistol grip (24)may cause the entire modified articulation control assembly (100) totranslate, which may thereby cause both articulation bands (212, 214) totranslate simultaneously in the same direction. Various suitable ways inwhich articulation control assembly (100) and trigger (28) may bemodified and coupled together will be apparent to those of ordinaryskill in the art in view of the teachings herein. Similarly, othersuitable ways in which articulation bands (212, 214) may be driven (inan opposing fashion and/or simultaneously in the same direction) will beapparent to those of ordinary skill in the art in view of the teachingsherein.

D. Exemplary Alternative End Effector and Shaft Assembly Configurationwith Dual Role Bands and Waveguide as Ground

FIGS. 13A-14B show another exemplary alternative shaft assembly (300)and end effector (340) that may be readily incorporated into instrument(10). Shaft assembly (300) of this example comprises a distal outersheath (302), a proximal outer sheath (304), and an articulation section(310) configured to operate substantially similar to articulationsections (130, 210) discussed above except for the differences discussedbelow. In particular, articulation section (310) is operable toselectively position end effector (340) at various lateral deflectionangles relative to a longitudinal axis defined by proximal outer sheath(304). End effector (340) includes an ultrasonic blade (342) and apivoting clamp arm (344) having a clamp pad (345). End effector (340) isconfigured to operate substantially similar to end effectors (40, 240)discussed above except for the differences discussed below. Inparticular, clamp arm (344) of end effector (340) is operable tocompress tissue against blade (342). When blade (342) is activated whileclamp arm (344) compresses tissue against blade (342), end effector(340) simultaneously severs the tissue and denatures the proteins inadjacent tissue cells, thereby providing a coagulative effect.

Clamp arm (344) is operable to selectively pivot toward and away fromblade (342) to selectively clamp tissue between clamp pad (345) andblade (342). Clamp arm (344) is pivotably secured to an upper distal endof a distal outer sheath (302) via a pin (322). A pair of arms (347)extend transversely from clamp arm (344) and are pivotably secured to acollar (320) via a pin (324). Collar (320) is slidably disposed withindistal outer sheath (302). Thus, it should be understood thatlongitudinal movement of collar (320) within distal outer sheath (302)causes pivoting of clamp arm (344) about pin (322) toward and away fromblade (342).

Blade (342) is positioned at the distal end of an acoustic drivetrain,which passes through an inner bore of collar (320) without contactingcollar (320). This acoustic drivetrain includes a transducer assembly(not shown) and an acoustic waveguide (346). Waveguide (346) comprises aflexible portion (348). Flexible portion (348) of waveguide (346)includes a distal flange (350), a proximal flange (not shown), and anarrowed section (349) located between distal flange (350) and theproximal flange. In the present example, distal flange (350) and theproximal flange are located at positions corresponding to nodesassociated with resonant ultrasonic vibrations communicated throughflexible portion (348) of waveguide (346). Narrowed section (349) isconfigured to allow flexible portion (348) of waveguide (346) to flexwithout significantly affecting the ability of flexible portion (348) ofwaveguide (346) to transmit ultrasonic vibrations. As best seen in FIGS.13A and 13B, distal flange (350) is secured to distal outer sheath (302)via a pin (352). Distal outer sheath (302) is thereby mechanicallygrounded to an instrument body (e.g., handle assembly (20), etc.) viawaveguide (346).

Shaft assembly (300) further comprises a pair of articulation bands(312, 314). Distal ends of articulation bands (312, 314) are secured tocollar (320). Articulation bands (312, 314) are configured to operatesubstantially similar to articulation bands (140, 142, 212, 214)discussed above except for the differences discussed below. Inparticular, as shown in FIGS. 14A-14B, opposing longitudinal motion ofarticulation bands (312, 314) causes articulation of articulationsection (310). Distal ends of articulation bands (312, 314) are securedto collar (320). When articulation bands (312, 314) are translatedlongitudinally in an opposing fashion, a moment is created and appliedto a distal end of distal outer sheath (302) via pin (322), arms (347)of clamp arm (344), pin (324), and collar (320). This causesarticulation section (310) and narrowed section (349) of flexibleportion (348) of waveguide (346) to articulate, without transferringaxial forces in articulation bands (312, 314) to waveguide (346).

As shown in FIGS. 13A-13B, when articulation bands (312, 314) are bothtranslated in the same direction simultaneously, this simultaneouslongitudinal movement of articulation bands (312, 314) causes concurrentlongitudinal movement of collar (320) relative to distal outer sheath(302) and the other grounded components of shaft assembly (300). Thus,the simultaneous longitudinal motion of articulation bands (312, 314) inthe same direction causes pivoting of clamp arm (344) toward and awayfrom ultrasonic blade (342). It should therefore be understood thatopposing longitudinal motion of articulation bands (312, 314) will causearticulation of articulation section (310); distal movement of botharticulation bands (312, 314) simultaneously will cause clamp arm (344)to pivot away from blade (342); and proximal movement of botharticulation bands (312, 314) simultaneously will cause clamp arm (344)to pivot toward blade (342).

Articulation bands (312, 314) may be driven to translate in an opposingfashion by a modified version of articulation control assembly (100).Articulation bands (312, 314) may be driven to translate in the samedirection simultaneously by a modified version of trigger (28). Forinstance, pivoting of trigger (28) toward and away from pistol grip (24)may cause the entire modified articulation control assembly (100) totranslate, which may thereby cause both articulation bands (312, 314) totranslate simultaneously in the same direction. Various suitable ways inwhich articulation control assembly (100) and trigger (28) may bemodified and coupled together will be apparent to those of ordinaryskill in the art in view of the teachings herein. Similarly, othersuitable ways in which articulation bands (312, 314) may be driven (inan opposing fashion and/or simultaneously in the same direction) will beapparent to those of ordinary skill in the art in view of the teachingsherein.

E. Exemplary Alternative End Effector and Shaft Assembly Configurationwith Clamp Arm Ball Joint

FIGS. 15A-16B show yet another exemplary alternative shaft assembly(400) and end effector (440) that may be readily incorporated intoinstrument (10). Shaft assembly (400) comprises a distal outer sheath(402), a proximal outer sheath (404), and an articulation section (410)configured to operate substantially similar to articulation sections(130, 210, 310) discussed above except for the differences discussedbelow. In particular, articulation section (410) is operable toselectively position end effector (440) at various lateral deflectionangles relative to a longitudinal axis defined by proximal outer sheath(404). End effector (440) includes an ultrasonic blade (442) and apivoting clamp arm (444) having a clamp pad (445). End effector (440) isconfigured to operate substantially similar to end effectors (40, 240,340) discussed above except for the differences discussed below. Inparticular, clamp arm (444) of end effector (440) is operable tocompress tissue against blade (442). When blade (442) is activated whileclamp arm (444) compresses tissue against blade (442), end effector(440) simultaneously severs the tissue and denatures the proteins inadjacent tissue cells, thereby providing a coagulative effect.

Clamp arm (444) is operable to selectively pivot toward and away fromblade (442) to selectively clamp tissue between clamp pad (445) andblade (442). A proximal end of clamp arm (444) comprises a socket (447)configured to engage a sphere-shaped collar (420). A distal end ofdistal outer sheath (402) comprises a socket (403) that is alsoconfigured to engage sphere-shaped collar (420), such that sphere-shapedcollar (420) is captured between sockets (403, 447). In other words,clamp arm (444), sphere-shaped collar (420), and distal outer sheath(402) engage one another in a ball-and-socket-like relationship. Theproximal end of clamp arm (444) is pivotably coupled with sphere-shapedcollar (420) and distal outer sheath (402) via a pin (422). Thus, itshould be understood that clamp arm (444) is operable to rotate aboutpin (422), along sphere-shaped collar (420), toward and away from blade(442). A bottom portion of clamp arm (444) is pivotably coupled within adistal end of a rod (413). Rod (413) is slidably disposed within shaftassembly (400) such that rod (413) is freely translatable relative toarticulation section (410). Thus, it should be understood thatlongitudinal movement of rod (413) causes pivoting of clamp arm (444)toward and away from blade (442) as shown in FIGS. 15A-15B. Rod (413) iscoupled with a trigger (not shown) such that clamp arm (444) ispivotable toward and away from ultrasonic blade (442) in response topivoting, sliding, or other actuation of the trigger.

Blade (442) is positioned at the distal end of an acoustic drivetrain,which passes through an inner bore of collar (420) without contactingcollar (420). This acoustic drivetrain includes a transducer assembly(not shown) and an acoustic waveguide (446). Waveguide (446) comprises aflexible portion (448). Flexible portion (448) of waveguide (446)includes a distal flange (450), a proximal flange (not shown), and anarrowed section (449) located between distal flange (450) and theproximal flange. In the present example, distal flange (450) and theproximal flange are located at positions corresponding to nodesassociated with resonant ultrasonic vibrations communicated throughflexible portion (448) of waveguide (446). Narrowed section (449) isconfigured to allow flexible portion (448) of waveguide (446) to flexwithout significantly affecting the ability of flexible portion (448) ofwaveguide (446) to transmit ultrasonic vibrations. As best seen in FIG.15A-15B, distal flange (450) engages an interior surface of distal outersheath (402). In some versions, a gap is defined between distal flange(450) and the interior surface of distal outer sheath (402). In someother versions, a dampening element such as an o-ring is interposedbetween distal flange (450) and the interior surface of distal outersheath (402).

Shaft assembly (400) further comprises a pair of articulation bands(412, 414). Distal ends of articulation bands (412, 414) are secured todistal outer sheath (402) and collar (420) via pin (422). Articulationbands (412, 414) are configured to operate substantially similar toarticulation bands (140, 142, 212, 214, 312, 314) discussed above exceptfor the differences discussed below. In particular, as shown in FIGS.16A and 16B, opposing longitudinal motion of articulation bands (412,414) is configured to cause articulation of articulation section (410).When articulation bands (412, 414) are translated longitudinally in anopposing fashion, a moment is created and applied to a distal end ofdistal outer sheath (402) via pin (422). This causes articulationsection (410) and narrowed section (449) of flexible portion (448) ofwaveguide (446) to articulate, without transferring axial forces inarticulation bands (412, 414) to waveguide (446). Articulation bands(212, 214) may be driven to translate in an opposing fashion by aversion of articulation control assembly (100) or by any other suitabledrive mechanism.

F. Fourth Exemplary Alternative End Effector and Shaft AssemblyConfiguration

FIGS. 17A-18 show yet another exemplary alternative shaft assembly (500)and end effector (540) that may be readily incorporated into instrument(10). Shaft assembly (500) comprises a distal outer sheath (502), aproximal outer sheath (504), and an articulation section (510)configured to operate substantially similar to articulation sections(130, 210, 310, 410) discussed above except for the differencesdiscussed below. In particular, articulation section (510) is operableto selectively position end effector (540) at various lateral deflectionangles relative to a longitudinal axis defined by proximal outer sheath(504). End effector (540) includes an ultrasonic blade (542) and apivoting clamp arm (544) having a clamp pad (545). End effector (540) isconfigured to operate substantially similar to end effectors (50, 240,340, 440) discussed above except for the differences discussed below. Inparticular, clamp arm (544) of end effector (540) is operable tocompress tissue against blade (542). When blade (542) is activated whileclamp arm (544) compresses tissue against blade (542), end effector(540) simultaneously severs the tissue and denatures the proteins inadjacent tissue cells, thereby providing a coagulative effect.

Clamp arm (544) is operable to selectively pivot toward and away fromblade (542) to selectively clamp tissue between clamp pad (545) andblade (542). Clamp arm (544) is pivotably secured to an upper distal endof a distal outer sheath (502) via a pin (522). A top portion of clamparm (544) is pivotably coupled within a distal end of a rod (513). Rod(513) is slidably secured to a top of shaft assembly (500) such that rod(513) is freely translatable relative to articulation section (510).Thus, it should be understood that longitudinal movement of rod (513)causes rotation of clamp arm (544) toward and away from blade (542). Rod(513) is coupled with a trigger (not shown) such that clamp arm (544) ispivotable toward and away from ultrasonic blade (542) in response topivoting, sliding, or other actuation of the trigger.

Blade (542) is positioned at the distal end of an acoustic drivetrain.This acoustic drivetrain includes a transducer assembly (not shown) andan acoustic waveguide (546). Waveguide (546) comprises a flexibleportion (548). Flexible portion (548) of waveguide (546) includes adistal flange (550), a proximal flange (552), and a narrowed section(549) located between flanges (550, 552). In the present example,flanges (550, 552) are located at positions corresponding to nodesassociated with resonant ultrasonic vibrations communicated throughflexible portion (548) of waveguide (546). Narrowed section (549) isconfigured to allow flexible portion (548) of waveguide (546) to flexwithout significantly affecting the ability of flexible portion (548) ofwaveguide (546) to transmit ultrasonic vibrations. It should beunderstood that rod (513) will also flex with flexible portion (548)when articulation section (510) is bent to an articulated state.

Shaft assembly (500) further comprises a pair of articulation cables(512). While only one articulation cable (512) is shown, it should beunderstood that another articulation cable (512) would be positioned onthe other side of shaft assembly (500), 180° from the articulation cable(512) that is shown. The distal ends of articulation cables (512) aresecured to distal flange (550) of waveguide (546). Articulation cables(512) are configured to operate substantially similar to articulationbands (140, 142, 212, 214, 312, 314, 412, 414) discussed above exceptfor the differences discussed below. Opposing longitudinal motion ofarticulation cables (512) is configured to cause articulation ofarticulation section (510). Articulation cables (512) are secured todistal outer sheath (502) via a collar (520). When articulation cables(512) are translated longitudinally in an opposing fashion, a moment iscreated and applied to a distal end of distal outer sheath (502) viadistal flange (550). This causes articulation section (510) and narrowedsection (549) of flexible portion (548) of waveguide (546) toarticulate, without transferring axial forces in articulation cables(512) to waveguide (546). Articulation bands (212, 214) may be driven totranslate in an opposing fashion by a version of articulation controlassembly (100) or by any other suitable drive mechanism.

In some versions of shaft assembly (500), shaft assembly includes anadditional outer sheath that is disposed about outer sheaths (502, 504)and articulation section (510). In some such versions, clamp arm (544)is pivotally coupled with this additional outer sheath instead of beingpivotally coupled with distal outer sheath (502). Rod (513) may befurther coupled with this additional outer sheath such that rod (513)may translate relative to the additional outer sheath to pivot clamp arm(544) toward and away from blade (542). This additional outer sheath maybe rotated relative to outer sheaths (502, 504) and articulation section(510). For instance, the additional outer sheath may include a knob toprovide such rotation (e.g., in addition to or in lieu of a knob thatprovides rotation of the entire shaft assembly (500) as a unit). Theadditional outer sheath may also be configured to flex at articulationsection (510), such that the additional outer sheath does notsignificantly impede the ability of articulation section (510) toachieve an articulated state. By way of example only, the additionalouter sheath may be formed of a thin metal tube (e.g., approximately0.002 inches thick) with laser cut features (e.g., a pattern of slots)that enable flexing at articulation section (510).

In versions where an additional outer sheath is provided as describedabove, clamp arm (544) and rod (513) may rotate with the additionalouter sheath relative to outer sheaths (502, 504) and articulationsection (510). Thus, the additional outer sheath may be used to rotateclamp arm (544) about the longitudinal axis of shaft assembly (500) toprovide clamp arm (544) at different orbital orientations about blade(542). In versions of blade (542) that have a non-circularcross-sectional profile, this ability to orient clamp arm (544) mayenable the operator to select a specific orientation that isparticularly suited for the task at hand. For instance, the operator mayorient clamp arm (544) to face a relatively broad flat face of blade(542) in order to provide relatively greater hemostasis in tissuecompressed between clamp arm (544) and blade (542); or orient clamp arm(544) to face a relatively narrow edge region of blade (542) in order toprovide relatively faster cutting of tissue compressed between clamp arm(544) and blade (542). Other suitable configurations and relationshipswill be apparent to those of ordinary skill in the art in view of theteachings herein. Similarly, other suitable ways in which an additionalouter sheath may be formed and incorporated into shaft assembly (500)will be apparent to those of ordinary skill in the art in view of theteachings herein. While this additional outer sheath is described in thecontext of shaft assembly (500), it should be understood that such anadditional outer sheath may also be incorporated into various othershaft assemblies described herein.

II. EXEMPLARY ALTERNATIVE SHAFT ASSEMBLY PROFILES

It may be desirable to change the profiles the components of shaftassembly (30). For instance, among other reasons, it may be desirable tochange the profiles of the components of shaft assembly (30) to providefor more clearance within shaft assembly (30) while still enclosing thecontents of shaft assembly (30) within an outer sheath. As will bediscussed in more detail below, FIGS. 19-27 show various examples of howthe profiles of the components of shaft assembly (30) may be changed.While various examples of how the profiles of the components of shaftassembly (30) may be changed will be described in greater detail below,other examples will be apparent to those of ordinary skill in the artaccording to the teachings herein. It should be understood that theexamples of shaft assemblies and/or articulation sections describedbelow may function substantially similar to shaft assembly (30)discussed above.

A. Exemplary Alternative Shaft Assembly Profile with Bands DefiningChannels

FIG. 19 shows an exemplary alternative profile of yet another exemplaryalternative shaft assembly (600) that may be used as a substitute forshaft assembly (30) in instrument (10). Shaft assembly (600) of thisexample comprises an outer sheath (602), a pair of articulation bands(604, 606), a waveguide (608), and a drive rod (610). Articulation bands(604, 606) are configured to operate substantially similar toarticulation bands (140, 142), such that opposing longitudinal motion ofarticulation bands (604, 606) causes articulation of shaft assembly(600). Rod (610) is configured to operate substantially similar to cable(174) discussed above, such that longitudinal translation of rod (610)causes actuation of a clamp arm (not shown).

Outer sheath (602) has a circular cross-sectional profile. Eacharticulation band (604, 606) comprises a large semi-circular portion(612, 614) and a small semi-circular portion (616, 618). Smallsemi-circular portions (616, 618) extend inwardly from largesemi-circular portions (612, 614). Articulation bands (604, 606) arearranged within outer sheath (602) such that small semi-circularportions (616, 618) are adjacent to one another, and form a channel(620) therebetween. Rod (610) is slidably disposed within channel (620)and is configured to longitudinally translate within channel (620) tothereby actuate the clamp arm. In the cross-sectional region shown inFIG. 19, waveguide (608) has a rectangular profile and passes withinouter sheath (602) between articulation bands (604, 606). It should beunderstood that waveguide (608) may have any other suitablecross-sectional profile that fits within the space defined betweenarticulation bands (604, 606). Moreover, the cross-sectional profile ofwaveguide (608) may vary along the length of waveguide (608).

B. Exemplary Alternative Shaft Assembly Profile Drive Features BetweenInner Tube and Outer Tube

FIG. 20 shows another exemplary alternative profile of yet anotherexemplary alternative shaft assembly (650) that may be used as asubstitute for shaft assembly (30) in instrument (10). Shaft assembly(650) of this example comprises an outer sheath (652), an inner tube(654), a pair of articulation bands (656, 658), a waveguide (660), and adrive rod (662). Articulation bands (656, 658) are configured to operatesubstantially similar to articulation bands (140, 142), such thatopposing longitudinal motion of articulation bands (656, 658) causesarticulation of shaft assembly (650). Rod (662) is configured to operatesubstantially similar to cable (174) discussed above, such longitudinaltranslation of rod (662) actuates a clamp arm (not shown).

Outer sheath (652) has a circular cross-sectional profile. Inner tube(654) is slidably disposed within outer sheath (652) such that a space(664) is defined between an interior surface of outer sheath (652) andan exterior surface of inner tube (654). Articulation bands (656, 658)are slidably disposed within space (664) between inner tube (654) andouter tube (652). A semi-circular channel (666) is formed in theexterior surface of inner tube (654). Rod (662) is slidably disposedwithin channel (666) and is configured to longitudinally translatewithin channel (666) to thereby actuate the clamp arm. In thecross-sectional region shown in FIG. 20, waveguide (660) has arectangular profile and passes within inner tube (654). It should beunderstood that waveguide (660) may have any other suitablecross-sectional profile that fits within the space defined within innertube (654). Moreover, the cross-sectional profile of waveguide (660) mayvary along the length of waveguide (660).

C. Exemplary Alternative Shaft Assembly Profile with Waveguide DefiningChannels and Dual Rods

FIG. 21 shows yet another exemplary alternative profile of yet anotherexemplary alternative shaft assembly (700) that may be used as asubstitute for shaft assembly (30) in instrument (10). Shaft assembly(700) of this example comprises an outer sheath (702), a pair ofarticulation bands (704, 706), a waveguide (708), and a pair of rods(710, 712). Articulation bands (704, 706) are configured to operatesubstantially similar to articulation bands (140, 142) discussed above,such that opposing longitudinal motion of articulation bands (704, 706)causes articulation of shaft assembly (700). Rods (710, 712) areconfigured to operate substantially similar to cable (174), such thatlongitudinal translation of rods (710, 712) provides actuation of aclamp arm (not shown). For instance, rod (710) may translate proximallywhile the other rod (712) translates distally to pivot a clamp arm awayfrom an ultrasonic blade; and rod (710) may translate distally while theother rod (712) translates proximally to pivot the clamp arm toward theultrasonic blade. Various suitable ways in which rods (710, 712) may bedriven in such an opposing fashion will be apparent to those of ordinaryskill in the art in view of the teachings herein. In some otherversions, one of the rods (710, 712) is substituted with one or morewires that is/are configured to provide RF electrosurgical capabilitiesat an end effector that is at the distal end of shaft assembly (700).

Outer sheath (702) has a circular cross-sectional profile. Waveguide(708) has a generally circular cross-sectional profile with a pair offlats (714, 716) and a pair of semi-circular channels (718, 720) definedwithin an exterior surface of waveguide (708). Rods (710, 712) areslidably disposed within respective channels (718, 720) and areconfigured to longitudinally translate within channels (718, 720) tothereby actuate the clamp arm. Waveguide (708) is disposed within outersheath (702) such that a space (722) is defined between an interiorsurface of outer sheath (702) and an exterior surface of waveguide(708). Articulation bands (704, 706) are slidably disposed within space(722) between outer sheath (702) and waveguide (708) adjacent to flats(714, 716) and are configured to longitudinally translate within space(722) to thereby cause articulation of shaft assembly (700).

D. Exemplary Alternative Shaft Assembly Profile with Waveguide DefiningChannels and Single Upper Rod

FIG. 22 shows yet another exemplary alternative profile of yet anotherexemplary alternative shaft assembly (750) that may be used as asubstitute for shaft assembly (30) in instrument (10). Shaft assembly(750) of this example comprises an outer sheath (752), a pair ofarticulation bands (754, 756), a waveguide (758), and a rod (760).Articulation bands (754, 756) are configured to operate substantiallysimilar to articulation bands (140, 142) discussed above, such thatopposing longitudinal motion of articulation bands (754, 756) causesarticulation of shaft assembly (750). Rod (760) is configured to operatesubstantially similar to cable (174), such that longitudinal translationof rod (760) provides actuation of a clamp arm (not shown).

Outer sheath (752) has a circular cross-sectional profile. Waveguide(758) has a generally circular cross-sectional profile with a pair offlats (764, 766) and a pair of semi-circular channels (768, 770) definedwithin an exterior surface of waveguide (758). Waveguide (758) isdisposed within outer sheath (752) such that a space (772) is definedbetween an interior surface of outer sheath (752) and an exteriorsurface of waveguide (758). Articulation bands (754, 756) are slidablydisposed within space (772) between outer sheath (752) and waveguide(758) adjacent to flats (764, 766) and are configured to longitudinallytranslate to thereby cause articulation of shaft assembly (750). Rod(760) is slidably disposed within channel (768) and is configured tolongitudinally translate within channel (768) to thereby actuate theclamp arm. In this example, no component is disposed in channel (770).Thus, channel (770) may simply be omitted if desired. Alternative, oneor more wires and/or other components may be positioned in channel(770).

E. Exemplary Alternative Shaft Assembly Profile with Waveguide DefiningChannels and Single Lower Rod

FIG. 23 shows yet another exemplary alternative profile of yet anotherexemplary alternative shaft assembly (800) that may be used as asubstitute for shaft assembly (30) in instrument (10). Shaft assembly(800) of this example comprises an outer sheath (802), a pair ofarticulation bands (804, 806), a waveguide (808), and a rod (810).Articulation bands (804, 806) are configured to operate substantiallysimilar to articulation bands (140, 142) discussed above, such thatopposing longitudinal motion of articulation bands (804, 806) causesarticulation of shaft assembly (800). Rod (810) is configured to operatesubstantially similar to cable (174) discussed above, such thatlongitudinal translation of rod (810) provides actuation of a clamp arm(not shown).

Outer sheath (802) has a circular cross-sectional profile. Waveguide(808) has a generally circular cross-sectional profile with a pair offlats (814, 816) and a pair of semi-circular channels (818, 820) definedwithin an exterior surface of waveguide (808). Waveguide (808) isdisposed within outer sheath (802) such that a space (822) is definedbetween an interior surface of outer sheath (802) and an exteriorsurface of waveguide (808). Articulation bands (804, 806) are slidablydisposed within space (822) between outer sheath (802) and waveguide(808) adjacent to flats (814, 816) and are configured to longitudinallytranslate to thereby cause articulation of shaft assembly (800). Rod(810) is slidably disposed within channel (820) and is configured tolongitudinally translate within channel (820) to thereby actuate theclamp arm. In this example, no component is disposed in channel (818).Thus, channel (818) may simply be omitted if desired. Alternative, oneor more wires and/or other components may be positioned in channel(818).

F. Exemplary Alternative Shaft Assembly Profile with Outer SheathDefining Channels for Upper and Lower Rods

FIG. 24 shows yet another exemplary alternative profile of yet anotherexemplary alternative shaft assembly (850) that may be used as asubstitute for shaft assembly (30) in instrument (10). Shaft assembly(850) of this example comprises an outer sheath (852), a pair ofarticulation bands (854, 856), a waveguide (858), and a pair of rods(860, 862). Articulation bands (854, 856) are configured to operatesubstantially similar to articulation bands (140, 142) discussed above,such that opposing longitudinal motion of articulation bands (854, 856)causes articulation of shaft assembly (850). Rods (860, 862) areconfigured to operate substantially similar to rods (710, 712) discussedabove, such that longitudinal translation of rods (860, 862) isconfigured to cause rotation of a clamp arm (not shown). For instance,rod (860) may translate proximally while the other rod (862) translatesdistally to pivot a clamp arm away from an ultrasonic blade; and rod(860) may translate distally while the other rod (862) translatesproximally to pivot the clamp arm toward the ultrasonic blade. Varioussuitable ways in which rods (860, 862) may be driven in such an opposingfashion will be apparent to those of ordinary skill in the art in viewof the teachings herein. In some other versions, one of the rods (860,862) is substituted with one or more wires that is/are configured toprovide RF electrosurgical capabilities at an end effector that is atthe distal end of shaft assembly (800).

Outer sheath (852) has a generally circular cross-sectional profile andincludes a pair of inwardly extending projections (864, 866).Projections (864, 866) each define a respective through bore (868, 870).In some versions, outer sheath (852) is formed in an extrusion process(e.g., from plastic and/or metal, etc.). Of course, any suitable processmay be used to form outer sheath (852). Rods (860, 862) are slidablydisposed within through bores (868, 870) and are configured tolongitudinally translate within through bores (868, 870) to therebyrotate the clamp arm. Articulation bands (854, 856) each have asemi-circular cross-sectional profile. Articulation bands (854, 856) areslidably disposed within outer sheath (852) between projections (864,866) and are configured to longitudinally translate to thereby causearticulation of shaft assembly (850).

In the cross-sectional region shown in FIG. 24, waveguide (858) has arectangular profile and passes within the space defined betweenarticulation bands (854, 856). It should be understood that waveguide(858) may have any other suitable cross-sectional profile that fitswithin the space defined between articulation bands (854, 856).Moreover, the cross-sectional profile of waveguide (858) may vary alongthe length of waveguide (858).

G. Exemplary Alternative Shaft Assembly Profile with Outer SheathDefining Channels for Dual Lower Rods

FIG. 25 shows yet another exemplary alternative profile of yet anotherexemplary alternative shaft assembly (900) that may be used as asubstitute for shaft assembly (30) in instrument (10). Shaft assembly(900) of this example comprises an outer sheath (902), a pair ofarticulation bands (904, 906), a waveguide (908), and a pair of rods(910, 912). Articulation bands (904, 906) are configured to operatesubstantially similar to articulation bands (140, 142) discussed above,such that opposing longitudinal motion of articulation bands (904, 906)causes articulation of shaft assembly (900). Rods (910, 912) areconfigured to operate substantially similar to cable (174) discussedabove, such that longitudinal translation of rods (910, 912) actuates aclamp arm (not shown).

Outer sheath (902) has a circular cross-sectional profile. Apartitioning member (914) extends between an interior surface of outersheath (902) along a chord line, and divides the interior of outersheath (902) into a first lumen (916) and a second lumen (918).Articulation bands (904, 906) each have a semi-circular profile.Articulation bands (904, 906) are slidably disposed within first lumen(916) of outer sheath (902) adjacent to one another and are configuredto longitudinally translate to thereby cause articulation of shaftassembly (900). Rods (910, 912) are slidably disposed within secondlumen (918) of outer sheath (902) and are configured to longitudinallytranslate within second lumen (918) to thereby actuate the clamp arm. Insome versions, both rods (910, 912) translate longitudinally in the samedirection simultaneously to actuate the clamp arm. In some otherversions, rods (910, 912) translate longitudinally in an opposingfashion to actuate the clamp arm. In still other versions, one of therods (910, 912) is substituted with one or more wires that is/areconfigured to provide RF electrosurgical capabilities at an end effectorthat is at the distal end of shaft assembly (900).

In the cross-sectional region shown in FIG. 25, waveguide (908) has arectangular profile and passes within the space defined betweenarticulation bands (904, 906) and partitioning member (914). It shouldbe understood that waveguide (908) may have any other suitablecross-sectional profile that fits within the space defined betweenarticulation bands (904, 906) and partitioning member (914). Moreover,the cross-sectional profile of waveguide (908) may vary along the lengthof waveguide (908).

H. Exemplary Alternative Shaft Assembly Profile with Partitioning MemberDefining Channel for Single Lower Ribbon

FIG. 26 shows yet another exemplary alternative profile of yet anotherexemplary alternative shaft assembly (950) that may be used as asubstitute for shaft assembly (30) in instrument (10). Shaft assembly(950) of this example comprises an outer sheath (952), a pair ofarticulation bands (954, 956), a waveguide (958), and a ribbon (960).Articulation bands (954, 956) are configured to operate substantiallysimilar to articulation bands (140, 142) discussed above, such thatopposing longitudinal motion of articulation bands (954, 956) causesarticulation of shaft assembly (950). Ribbon (960) is configured tooperate substantially similar to cable (174), such that longitudinaltranslation of ribbon (960) actuates a clamp arm (not shown).

Outer sheath (952) has a circular cross-sectional profile. Apartitioning member (964) extends between an interior surface of outersheath (952) along a chord line, and divides the interior of outersheath (952) into a first lumen (966) and a second lumen (968).Articulation bands (954, 956) each have a semi-circular profile.Articulation bands (954, 956) are slidably disposed within first lumen(966) of outer sheath (952) adjacent to one another and are configuredto longitudinally translate to thereby cause articulation of shaftassembly (950). Ribbon (960) is slidably disposed within second lumen(968) of outer sheath (952) and is configured to longitudinallytranslate within second lumen (968) to thereby actuate the clamp arm.

In the cross-sectional region shown in FIG. 26, waveguide (958) has arectangular profile and passes within the space defined betweenarticulation bands (954, 956) and partitioning member (964). It shouldbe understood that waveguide (908) may have any other suitablecross-sectional profile that fits within the space defined betweenarticulation bands (954, 956) and partitioning member (964). Moreover,the cross-sectional profile of waveguide (958) may vary along the lengthof waveguide (958).

I. Exemplary Alternative Shaft Assembly Profile with Outer SheathDefining Channel for Single Lower Rod

FIG. 27 shows yet another exemplary alternative profile of yet anotherexemplary alternative shaft assembly (1000) that may be used as asubstitute for shaft assembly (30) in instrument (10). Shaft assembly(1000) of this example comprises an outer sheath (1002), a pair ofarticulation bands (1004, 1006), a waveguide (1008), and a ribbon(1010). Articulation bands (1004, 1006) are configured to operatesubstantially similar to articulation bands (140, 142) discussed above,such that opposing longitudinal motion of articulation bands (1004,1006) causes articulation of shaft assembly (1000). Ribbon (1010) isconfigured to operate substantially similar to cable (174) discussedabove, such that longitudinal translation of ribbon (1010) actuates aclamp arm (not shown).

Outer sheath (1002) defines a first lumen (1012) and a second lumen(1014). In some versions, outer sheath (1002) is formed in an extrusionprocess (e.g., from plastic and/or metal, etc.). Of course, any suitableprocess may be used to form outer sheath (852). Articulation bands(1004, 1006) each have a semi-circular profile. Articulation bands(1004, 1006) are slidably disposed within first lumen (1012) of outersheath (1002) adjacent to one another and are configured tolongitudinally translate to thereby cause articulation of shaft assembly(1000). Ribbon (1010) is slidably disposed within second lumen (1014) ofouter sheath (1002) and is configured to longitudinally translate withinsecond lumen (1018) to thereby actuate the clamp arm.

In the cross-sectional region shown in FIG. 27, waveguide (1008) has arectangular profile and passes within the space defined betweenarticulation bands (1004, 1006). It should be understood that waveguide(1008) may have any other suitable cross-sectional profile that fitswithin the space defined between articulation bands (1004, 1006).Moreover, the cross-sectional profile of waveguide (1008) may vary alongthe length of waveguide (1008).

III. EXEMPLARY ALTERNATIVE ACTUATION OF CLAMP ARM

It may be desirable to alter the operation of clamp arm (44) and/orarticulation section (130). As will be discussed in more detail below,FIGS. 28-33B show various examples of how the operation of clamp arm(44) may be altered. While various examples of how the operation ofclamp arm (44) may be altered will be described in greater detail below,other examples will be apparent to those of ordinary skill in the artaccording to the teachings herein. It should be understood that theexamples of clamp arms described below may function substantiallysimilar to clamp arm (44) discussed above. In particular, the examplesof clamp arms described below are operable to compress tissue against anultrasonic blade to thereby simultaneously sever the tissue and denaturethe proteins in adjacent tissue cells, thereby providing a coagulativeeffect.

A. Exemplary Alternative Clamp Arm Drive Assembly with Rod and ArcuateArms

FIGS. 28 and 29 show an exemplary rod (1050) and clamp arm (1060) thatmay be readily incorporated into instrument (10). Clamp arm (1060) isconfigured to operate substantially similar to clamp arm (44) discussedabove, such that clamp arm (1060) is operable to selectively pivottoward and away from a blade (not shown) to selectively clamp tissuebetween clamp arm (1060) and the blade. Rod (1050) is configured tooperate substantially similar to cable (174), such that longitudinaltranslation of rod (1050) causes actuation of clamp arm (1060) towardand away from the blade.

In the present example, a coupler (1052) is disposed at a distal end ofrod (1050). Coupler (1052) comprises a pair of circular recesses (1054,1056) formed in opposite sides of coupler (1052). A pair of arcuate arms(1062, 1064) extend transversely from clamp arm (1060). A circularprojection (1066, 1068) extends inwardly from an interior surface ofeach arcuate arm (1062, 1064). Circular projections (1066, 1068) arerotatably disposed with respective circular recesses (1054, 1056) ofcoupler (1052). As discussed above with reference to instrument (10),clamp arm (1060) would be rotatably secured to a distal end of alongitudinally grounded shaft assembly (not shown), such thatlongitudinal movement of rod (1050) and coupler (1052) would pivotallyactuate clamp arm (1060) toward and away from the blade.

B. Exemplary Alternative Clamp Arm Drive Assembly with Bent Rods

FIGS. 30 and 31 show additional examples of configurations that may beused to couple a pair of rods with a clamp arm to actuate the clamp arm.In the example shown in FIG. 30, a pair of rods (1100, 1102) eachcomprise a dog-leg feature (1104, 1106) at a distal end of rods (1100,1102). A clamp arm (1110) comprises a pair of openings (1112, 1114).Dog-leg features (1104, 1106) of rods (1100, 1102) are pivotablydisposed in openings (1112, 1114) of clamp arm (1110). As discussedabove with reference to instrument (10), clamp arm (1110) would berotatably secured to a distal end of a longitudinally grounded shaftassembly (not shown), such that longitudinal movement of rods (1100,1102) would pivotally actuate clamp arm (1110) toward and away from ablade (not shown). In the present example, rods (1100, 1102) aredirectly coupled with clamp arm (1110). In some other versions, rods(1100, 1102) are coupled with clamp arm (1110) via some intermediarycomponent. For instance, rods (1100, 1102) may instead be directlycoupled with a collar or inner tube section, which may in turn bepivotally coupled with clamp arm (1110). Other suitable relationshipswill be apparent to those of ordinary skill in the art in view of theteachings herein.

In the example shown in FIG. 31, a pair of rods (1120, 1122) eachcomprise an outwardly projecting tab (1124, 1126) at a distal end ofrods (1120, 1122). A clamp arm (1130) comprises a pair of openings(1132, 1134). Outwardly projecting tabs (1124, 1126) of rods (1120,1122) are pivotably disposed in openings (1132, 1134) of clamp arm(1130). As discussed above with reference to instrument (10), clamp arm(1130) would be rotatably secured to a distal end of a longitudinallygrounded shaft assembly (not shown), such that longitudinal movement ofrods (1120, 1122) would pivotally actuate clamp arm (1130) toward andaway from a blade (not shown). In the present example, rods (1120, 1122)are directly coupled with clamp arm (1130). In some other versions, rods(1120, 1122) are coupled with clamp arm (1130) via some intermediarycomponent. For instance, rods (1120, 1122) may instead be directlycoupled with a collar or inner tube section, which may in turn bepivotally coupled with clamp arm (1130). Other suitable relationshipswill be apparent to those of ordinary skill in the art in view of theteachings herein.

C. Exemplary Alternative Clamp Arm with Oblique Coupling Projection

FIGS. 32-33B show yet another exemplary alternative clamp arm (1150)that may be readily incorporated into instrument (10). Clamp arm (1150)of this example includes a clamp pad (1152) that is secured to theunderside of clamp arm (1150). As shown in FIGS. 33A-33B, clamp arm(1150) is pivotably secured to a distal end of an exemplary alternativeshaft assembly (1160). A tubular projection (1154) extends obliquelyfrom clamp arm (1150) and is pivotably secured to a rod (1162). Rod(1162) is operable to translate longitudinally to thereby selectivelypivot clamp arm (1150) toward and away from a blade (1164). As shown inFIG. 33A, tubular projection (1154) extends from clamp arm (1150) at anoblique angle relative to the longitudinal axis of shaft assembly (1160)when clamp arm (1150) is in a closed position. As shown in FIG. 33B,tubular projection (1154) extends from clamp arm (1150) perpendicularlyto the longitudinal axis of shaft assembly (1160) when clamp arm (1150)is in an open position. It should be appreciated that, with tubularprojection (1154) extending from clamp arm (1150) at an oblique anglerelative to shaft assembly (1160), tubular projection (1154) will notcontact blade (1164) when clamp arm (1150) is opened to a substantiallywide open position.

D. Exemplary Alternative Articulation Section Drivers with Racks andIdler

FIGS. 34A-37 show yet another exemplary alternative shaft assembly(1200) and end effector (1210) that may be readily incorporated intoinstrument (10). Shaft assembly (1200) comprises a pair of articulationdrive bands (1202, 1204) and a pair of jaw closure bands (1206, 1208). Adistal end of each a articulation drive band (1202, 1204) is secured toa distal end of shaft assembly (1200) via a distal flange (1203) of aflexible waveguide (1230). When articulation drive bands (1202, 1204)are translated longitudinally in an opposing fashion, a moment iscreated and applied to the distal end of shaft assembly (1200) viadistal flange (1203). Thus, opposing longitudinal motion of articulationdrive bands (1202, 1204) causes articulation of shaft assembly (1200).Articulation drive bands (1202, 1204) may be driven using a version ofarticulation control assembly (100) described above or any othersuitable mechanism.

Jaw closure bands (1206, 1208) pass slidably through flange (1203). Adistal end of each jaw closure band (1206, 1208) is pivotally secured toa clamp arm (1212). It should be understood that FIGS. 34A-34B only showtransverse coupling arms (1213) of clamp arm (1212). As discussed abovewith reference to instrument (10), clamp arm (1212) would be rotatablysecured to a distal end of a longitudinally grounded shaft assembly(1200), such that simultaneous longitudinal translation of jaw closurebands (1206, 1208) pivotally actuates clamp arm (1212) toward and awayfrom an ultrasonic blade (1214).

As shown in FIG. 36, jaw closure bands (1206, 1208) may be pivotablysecured to a bottom pivot opening (1218) in each arm (1213) of clamp arm(1212) in those versions of end effector (1210) where a top portion ofclamp arm (1212) is pivotably secured to shaft assembly (1200) via a toppivot opening (1216) in each arm (1213), such that simultaneouslongitudinal translation of jaw closure bands (1206, 1208) causespivoting of clamp arm (1212) toward and away from an ultrasonic blade(1214). As shown in FIG. 37, jaw closure bands (1206, 1208) may bepivotably secured to top pivot opening (1216) in each arm (1213) ofclamp arm (1212) in those versions of end effector (1210) where a bottomportion of clamp arm (1212) is pivotably secured to shaft assembly(1200) via bottom pivot opening (1218) in each arm (1213), such thatsimultaneous longitudinal translation of jaw closure bands (1206, 1208)causes pivoting of clamp arm (1212) toward and away from an ultrasonicblade (1214).

Referring back to FIGS. 34A-34B, the proximal region of each jaw closureband (1206, 1208) includes a respective, inwardly directed rack (1207,1209). Shaft assembly (1200) of the present example further comprises agear (1220) positioned between racks (1207, 1209) of articulation jawclosure bands (1206, 1208). Gear (1220) comprises a plurality of teeth(1222) that mesh with complementary teeth of racks (1207, 1209). Gear(1220) is configured to rotate freely about a central axle (1221), suchthat gear (1220) serves as an idler. Thus, as shaft assembly (1200) isarticulated by opposing longitudinal translation of articulation bands(1202, 1204), gear (1220) engages second pair of articulation bands(1206, 1208) and provides for guided, opposing longitudinal translationof jaw closure bands (1206, 1208) as shown in FIG. 34B. In other words,gear (1220) allows jaw closure bands (1206, 1208) to move in relation toeach other to accommodate articulation of shaft assembly (1200).

Also in the present example, gear (1220) is operable to drive jawclosure bands (1206, 1208) longitudinally in the same direction in orderto actuate clamp arm (1212). In particular, axle (1221) is configured toslide longitudinally relative to shaft assembly (1200), therebyproviding longitudinal movement of gear (1220) relative to shaftassembly (1200). Due to engagement of teeth (1222) with racks, (1207,1209), this will provide corresponding and simultaneous longitudinalmovement of both jaw closure bands (1206, 1208) relative to shaftassembly (1200). Various suitable features that may be used to driveaxle (1221) longitudinally will be apparent to those of ordinary skillin the art in view of the teachings herein.

FIG. 35 shows a cross-sectional view of shaft assembly (1200). At thiscross-sectional region, waveguide (1230) has an I-shaped cross-sectionalprofile with a pair of rectangular channels (1232, 1234) defined onopposite sides of waveguide (1230). Articulation bands (1202, 1204) areslidably disposed within channel (1232) between waveguide (1230) and aninterior surface of an outer sheath (1211). Articulation bands (1206,1208) are slidably disposed within channel (1234) between waveguide(1230) and an interior surface of an outer sheath (1211). Of course, anyother suitable configurations may be used.

E. Exemplary Shaft Assembly with Clamp Arm Actuation Via Flexible OuterSheath

FIGS. 38-39 show yet another exemplary alternative shaft assembly (1250)and end effector (1270) that may be readily incorporated into instrument(10). Shaft assembly (1250) comprises an outer sheath (1260), a pair ofribbed body portions (1252, 1254), a pair of articulation bands (1256,1258), and a waveguide (1280). End effector (1270) includes anultrasonic blade (1282) and a pivoting clamp arm (1272) having a clamppad (1274). End effector (1270) is configured to operate substantiallysimilar to end effector (40), such clamp arm (1272) of end effector(1270) is operable to compress tissue against blade (1282). When blade(1282) is activated while clamp arm (1272) compresses tissue againstblade (1282), end effector (1270) simultaneously severs the tissue anddenatures the proteins in adjacent tissue cells, thereby providing acoagulative effect.

Clamp arm (1272) is operable to selectively pivot toward and away fromblade (1282) to selectively clamp tissue between clamp arm (1272) andblade (1282). A pair of arms (1273) extend transversely from clamp arm(1272). Arms (1273) are pivotably secured to a distally projectingtongue (1277) of a collar (1276). Collar (1276) is secured to a distalflange (1286) of waveguide (1280). Waveguide (1280) provides alongitudinal mechanical ground for collar (1276), which in turn providesa longitudinal mechanical ground to clamp arm (1272). Clamp arm (1272)is also pivotably secured with a distally projecting tongue (1261) ofouter sheath (1260). Outer sheath (1260) is operable to translatelongitudinally relative to waveguide (1280) and the other components ofshaft assembly (1250) that are longitudinally mechanically grounded. Itshould therefore be understood that outer sheath (1260) is operable toactuate clamp arm (1272) toward and away from blade (1282). A triggersuch as trigger (28) or any other suitable feature may be operable totranslate outer sheath (1260) longitudinally, to thereby actuate clamparm (1272) toward and away from blade (1282).

Blade (1282) is positioned at the distal end of an acoustic drivetrain.This acoustic drivetrain includes a transducer assembly (not shown) andwaveguide (1280). Waveguide (1280) comprises a flexible portion (1284).Flexible portion (1284) of waveguide (1280) includes a distal flange(1286), a proximal flange (1288), and a narrowed section (1285) locatedbetween distal flanges (1286, 1288). In the present example, flanges(1286, 1288) are located at positions corresponding to nodes associatedwith resonant ultrasonic vibrations communicated through flexibleportion (1284) of waveguide (1280). Narrowed section (1285) isconfigured to allow flexible portion (1284) of waveguide (1280) to flexwithout significantly affecting the ability of flexible portion (1284)of waveguide (1280) to transmit ultrasonic vibrations.

Outer sheath (1260) further comprises an articulation section (1262)having a series of interlocking rings (1264). Rings (1264) areconfigured to engage one another in a manner such that articulationsection (1262) is operable to selectively flex at various lateraldeflection angles relative to a longitudinal axis defined by shaftassembly (1250). Rings (1264) also allow outer sheath (1260) totranslate along a bent region of shaft assembly (1250) when shaftassembly (1250) is in an articulated state.

Ribbed body portions (1252, 1254) are configured to selectively flex atvarious lateral deflection angles relative to the longitudinal axisdefined by shaft assembly (1250) and to further provide for guidance ofarticulation bands (1256, 1258). In particular, ribbed body portions(1252, 1254) prevent articulation bands (1256) from contacting theregion of waveguide (1280) between flanges (1286, 1288).

Articulation bands (1256, 1258) are configured to operate substantiallysimilar to articulation bands (140, 142), such opposing longitudinalmotion of articulation bands (1256, 1258) causes articulation of shaftassembly (1250). Articulation bands (1256, 1258) each comprise aflexible portion (1257, 1259) that is configured to align with thearticulation section of shaft assembly (1250). Distal ends ofarticulation bands (1256, 1258) are secured to collar (1276). Whenarticulation bands (1256, 1258) are translated longitudinally in anopposing fashion, a moment is created and applied to distal flange(1286) via collar (1276). This causes the articulation section of shaftassembly (1250), in particular articulation section (1262), ribbed bodyportions (1252, 1254), flexible portion (1257, 1259) of articulationbands (1256, 1258), and narrowed section (1285) of flexible portion(1284) of waveguide (1280), to articulate, without transferring axialforces in articulation bands (1256, 1258) to waveguide (1280).

F. Exemplary Alternative Configuration for Outer Closure Tube forActuation of Clamp Arm

FIG. 40 shows yet another exemplary alternative shaft assembly (1300)and end effector (1340) that may be readily incorporated into instrument(10). Shaft assembly (1300) of this example comprises an outer sheath(1302) that is configured to translate longitudinally relative to endeffector (1340) to pivotally actuate a clamp arm (1342) toward and awayfrom an ultrasonic blade (1346). Shaft assembly (1300) and end effector(1340) thus operate similar to shaft assembly (1250) and end effector(1270) described above. However, in this example, a distal end of outersheath (1302) defines a slot (1304). Clamp arm (1342) of end effector(1340) comprises a proximal projection (1344) extending upwardly fromclamp arm (1342). Proximal projection (1344) is disposed within slot(1304). As discussed above with reference to instrument (10), clamp arm(1304) is pivotally secured to a longitudinally grounded component ofshaft assembly (1300), such that longitudinal translation of outersheath (1302) causes pivoting of clamp arm (1342) toward and away fromblade (1346) via engagement of projection (1344) with slot (1304). Othersuitable ways in which clamp arm (1342) may be coupled with atranslating outer sheath (1302) will be apparent to those of ordinaryskill in the art in view of the teachings herein.

G. Exemplary Alternative Actuation of Articulation Section

FIGS. 41-42B show exemplary alternative internal components of yetanother exemplary alternative shaft assembly (1400) and end effector(1440) that may be readily incorporated into instrument (10). Endeffector (1440) of this example comprises an ultrasonic blade (1442) anda clamp arm (1444). Clamp arm (1444) includes a clamp pad (1446) that issecured to the underside of clamp arm (1444), facing blade (1442). Blade(1442) of the present example is configured to operate substantiallysimilar to blade (160) discussed above, such that blade (1442) isoperable to vibrate at ultrasonic frequencies in order to effectivelycut through and seal tissue, particularly when the tissue is beingcompressed between clamp pad (1446) and blade (1442). Blade (1442) ispositioned at the distal end of an acoustic drivetrain. This acousticdrivetrain includes transducer assembly (12) and an acoustic waveguide(1410). The transducer assembly is operable to convert electrical powerinto ultrasonic vibrations, which are then transmitted along waveguide(1410), including flexible portion (1412) of waveguide (1410), to blade(1442) in accordance with known configurations and techniques. By way ofexample only, this portion of the acoustic drivetrain may be configuredin accordance with various teachings of various references that arecited herein.

Waveguide (1410) comprises a flexible portion (1412), a distal flange(1414), and a proximal flange (1416). As best seen in FIGS. 42A and 42B,flexible portion (1412) of waveguide (1410) includes a narrowed section(1418) located between flanges (1414, 1416). In the present example,flanges (1414, 1416) are located at positions corresponding to nodesassociated with resonant ultrasonic vibrations communicated throughflexible portion (1412) of waveguide (1410). Narrowed section (1418) isconfigured to allow flexible portion (1412) of waveguide (1410) to flexwithout significantly affecting the ability of flexible portion (1412)of waveguide (1410) to transmit ultrasonic vibrations. By way of exampleonly, narrowed section (1418) may be configured in accordance with oneor more teachings of U.S. Pub. No. 2014/0005701, issued as U.S. Pat. No.9,393,037 on Jul. 19, 2016, and/or U.S. Pub. No. 2014/0114334, issued asU.S. Pat. No. 9,095,367 on Aug. 4, 2015, the disclosures of which areincorporated by reference herein. It should be understood that waveguide(1410) may be configured to amplify mechanical vibrations transmittedthrough waveguide (1410). Furthermore, waveguide (1410) may includefeatures operable to control the gain of the longitudinal vibrationsalong waveguide (1410) and/or features to tune waveguide (1410) to theresonant frequency of the system.

In the present example, the distal end of blade (1442) is located at aposition corresponding to an anti-node associated with resonantultrasonic vibrations communicated through flexible portion (1412) ofwaveguide (1410), in order to tune the acoustic assembly to a preferredresonant frequency f_(o) when the acoustic assembly is not loaded bytissue. When transducer assembly (12) is energized, the distal end ofblade (1442) is configured to move longitudinally in the range of, forexample, approximately 10 to 500 microns peak-to-peak, and in someinstances in the range of about 20 to about 200 microns at apredetermined vibratory frequency f_(o) of, for example, 55.5 kHz. Whentransducer assembly (12) of the present example is activated, thesemechanical oscillations are transmitted through waveguide (1410) toreach blade (1442), thereby providing oscillation of blade (1442) at theresonant ultrasonic frequency. Thus, when tissue is compressed betweenblade (1442) and clamp pad (1446), the ultrasonic oscillation of blade(1442) may simultaneously sever the tissue and denature the proteins inadjacent tissue cells, thereby providing a coagulative effect withrelatively little thermal spread. In some versions, an electricalcurrent may also be provided through blade (1442) and clamp arm (1444)to also cauterize the tissue. Other suitable configurations for anacoustic transmission assembly and transducer assembly will be apparentto one or ordinary skill in the art in view of the teachings herein.Similarly, other suitable configurations for end effector (1440) will beapparent to those of ordinary skill in the art in view of the teachingsherein.

The internal components of shaft assembly (1400) further comprise a pairof articulation cables (1430, 1432). Proximal flange (1416) of flexibleportion (1412) of waveguide (1410) comprises a plurality of throughbores (1420, 1422, 1424). The distal ends of articulation cables (1430,1432) are unitarily secured to distal flange (1414) of flexible portion(1412) of waveguide (1410). Articulation cables (1430, 1432) extendproximally from distal flange (1414) and pass freely through bores(1420, 1422) within shaft assembly (1400). As one articulation cable(1430, 1432) is pulled proximally, this will cause an articulationsection of shaft assembly (1400) to bend, thereby laterally deflectingend effector (1440) away from a longitudinal axis of shaft assembly(1400) at an articulation angle as shown in FIG. 42B. In particular, endeffector (1440) will be articulated toward the articulation cable (1430,1432) that is being pulled proximally. During such articulation, theother articulation cable (1430, 1432) will be pulled distally by distalflange (1414) of flexible portion (1412) of waveguide (1410). Flexibleportion (1412) is configured to effectively communicate ultrasonicvibrations from waveguide (1410) to blade (1442) even when thearticulation section of shaft assembly (1440) is in an articulated stateas shown in FIG. 42B.

Distal flange (1414) of flexible portion (1412) of waveguide (1410) isfixedly secured to a distal end of shaft assembly (1400). Whenarticulation cables (1430, 1432) are translated longitudinally in anopposing fashion, a moment is created and applied to the distal endshaft assembly (1400) via distal flange (1414). This causes thearticulation section of shaft assembly (1400) and narrowed section(1418) of flexible portion (1412) of waveguide (1410) to articulate,without transferring axial forces in articulation cables (1430, 1432) towaveguide (1410). It should be understood that one articulation cable(1430, 1432) may be actively driven distally while the otherarticulation cable (1430, 1432) is passively permitted to retractproximally. As another merely illustrative example, one articulationcable (1430, 1432) may be actively driven proximally while the otherarticulation cable (1430, 1432) is passively permitted to advancedistally. As yet another merely illustrative example, one articulationcable (1430, 1432) may be actively driven distally while the otherarticulation cable (1430, 1432) is actively driven proximally. Varioussuitable ways in which articulation cables (1430, 1432) may be drivenwill be apparent to those of ordinary skill in the art in view of theteachings herein. It should also be understood that one or more spacersmay be used to prevent articulation cables (1430, 1432) from contactingwaveguide (1410) between flanges (1414, 1416).

An upper portion of clamp arm (44) is pivotally secured to a distallyprojecting tongue (1443) of distal flange (1414) of waveguide (1410).Clamp arm (1444) is operable to selectively pivot toward and away fromblade (1442) to selectively clamp tissue between clamp pad (1446) andblade (1442). A cable (1428) is secured to a lower portion of clamp arm(1444). Cable (1428) extends proximally from clamp arm (1444) and passesfreely through distal flange (1414) and freely through bore (1424) ofproximal flange (1416) within shaft assembly (1400). Cable (1428) isoperable to translate longitudinally relative to the articulationsection of shaft assembly (1400) to selectively pivot clamp arm (1444)toward and away from blade (1442). Cable (1428) may be coupled with atrigger such that clamp arm (1444) pivots toward and away from blade(1442) in response to pivoting of the trigger. Clamp arm (1444) may bebiased toward the open position, such that (at least in some instances)the operator may effectively open clamp arm (1444) by releasing a gripon the trigger.

IV. EXEMPLARY ALTERNATIVE WAVEGUIDE CONFIGURATIONS

It may be desirable to provide for alternative engagement betweenwaveguide (180) and shaft assembly (30). As will be discussed in moredetail below, FIGS. 43-50 show various examples of how waveguide (180)may engage shaft assembly (30). While various examples of how waveguide(180) may engage shaft assembly (30) will be described in greater detailbelow, other examples will be apparent to those of ordinary skill in theart according to the teachings herein. It should be understood that theexamples of waveguides described below may function substantiallysimilar to clamp waveguide (180) discussed above. In particular, theexamples of waveguides described below are operable to transmitultrasonic vibrations from transducer (12) to an ultrasonic blade.

FIGS. 43-46 show an exemplary alternative waveguide (1500) that may bereadily incorporated into instrument (10). Waveguide (1500) of thisexample comprises an ultrasonic blade (1502) and a flexible portion(1504). Blade (1502) of the present example is configured to operatesubstantially similar to blade (160) discussed above except for thedifferences discussed below. In particular, blade (1502) of the presentexample is operable to vibrate at ultrasonic frequencies in order toeffectively cut through and seal tissue. As discussed above, transducerassembly (12) is operable to convert electrical power into ultrasonicvibrations, which are then transmitted along waveguide (1502), includingflexible portion (1504) of waveguide (1502) to blade (1502) inaccordance with known configurations and techniques. By way of exampleonly, this portion of the acoustic drivetrain may be configured inaccordance with various teachings of various references that are citedherein.

As best seen in FIG. 43, flexible portion (1504) of waveguide (1500)includes a distal flange (1506), a proximal flange (1508), and anarrowed section (1510) located between flanges (1506, 1508). In thepresent example, flanges (1506, 1508) are located at positionscorresponding to nodes associated with resonant ultrasonic vibrationscommunicated through flexible portion (1504) of waveguide (1500).Narrowed section (1510) is configured to allow flexible portion (1504)of waveguide (1500) to flex without significantly affecting the abilityof flexible portion (1504) of waveguide (1500) to transmit ultrasonicvibrations. By way of example only, narrowed section (1510) may beconfigured in accordance with one or more teachings of U.S. Pub. No.2014/0005701, issued as U.S. Pat. No. 9,393,037 on Jul. 19, 2016, and/orU.S. Pub. No. 2014/0114334, issued as U.S. Pat. No. 9,095,367 on Aug. 4,2015, the disclosures of which are incorporated by reference herein. Itshould be understood that waveguide (1500) may be configured to amplifymechanical vibrations transmitted through waveguide (1500). Furthermore,waveguide (1500) may include features operable to control the gain ofthe longitudinal vibrations along waveguide (1500) and/or features totune waveguide (1500) to the resonant frequency of the system.

In the present example, the distal end of blade (1502) is located at aposition corresponding to an anti-node associated with resonantultrasonic vibrations communicated through flexible portion (1504) ofwaveguide (1500), in order to tune the acoustic assembly to a preferredresonant frequency f_(o) when the acoustic assembly is not loaded bytissue. When transducer assembly (12) is energized, the distal end ofblade (1502) is configured to move longitudinally in the range of, forexample, approximately 10 to 500 microns peak-to-peak, and in someinstances in the range of about 20 to about 200 microns at apredetermined vibratory frequency f_(o) of, for example, 55.5 kHz. Whentransducer assembly (12) of the present example is activated, thesemechanical oscillations are transmitted through waveguide (1500) toreach blade (1502), thereby providing oscillation of blade (1502) at theresonant ultrasonic frequency. Thus, the ultrasonic oscillation of blade(1502) may simultaneously sever the tissue and denature the proteins inadjacent tissue cells, thereby providing a coagulative effect withrelatively little thermal spread. In some versions, an electricalcurrent may also be provided through blade (1502) to also cauterize thetissue. While some configurations for an acoustic transmission assemblyand transducer assembly (12) have been described, still other suitableconfigurations for an acoustic transmission assembly and transducerassembly (12) will be apparent to one or ordinary skill in the art inview of the teachings herein.

Waveguide (1500) further comprises a pair of overmolds (1512, 1514)secured about an exterior of flanges (1506, 1508). Overmolds (1512,1514) of flanges (1506, 1508) are configured to engage an interiorsurface of shaft assembly (30). Overmolds (1512, 1514) provide anacoustic barrier between waveguide (1500) and shaft assembly (30) tothereby lessen the effect that engagement between waveguide (1500) andshaft assembly (30) may have upon transmission of ultrasonic vibrationswithin waveguide (1500). As shown in FIG. 44, flanges (1506, 1508) ofthe present example comprise an annular groove (1507) formed in anexterior surface of flanges (1506, 1508). Overmolds (1512, 1514) may bedisposed within groove (1507) to thereby improve engagement betweenovermolds (1512, 1514) and flanges (1506, 1508). Overmolds (1512, 1514)may comprise polytetraflouroethylene (PTFE), rubber, silicone, plastic,and/or any other suitable material(s).

As best seen in FIG. 46, flanges (1506, 1508) of the present examplehave a circular cross-sectional profile. It should be understood,however, that any other suitable shapes may be used. For instance, FIGS.47-48 show an exemplary alternative waveguide (1550) with a flange(1556) having an oblong shape. In particular, flange (1556) includes apair of flats (1557). A blade (1552) is located distal to flange (1556).An overmold (1562) is positioned about flange (1556) and has across-sectional profile complementing the cross-sectional profile offlange (1556). FIGS. 49-50 show another exemplary alternative waveguide(1600) with a flange (1606) having an oblong shape. In particular,flange (1606) includes a pair of flats (1607) and a pair oflongitudinally extending grooves (1609). A blade (1602) is locateddistal to flange (1606). An overmold (1612) is positioned about flange(1606) and has a cross-sectional profile complementing thecross-sectional profile of flange (1606). Other suitable configurationsthat may be used for flanges will be apparent to those of ordinary skillin the art in view of the teachings herein.

V. EXEMPLARY ALTERNATIVE INSTRUMENT WITH DUAL ROLE BANDS AND DUALACTUATORS

FIGS. 51-53 show another exemplary ultrasonic surgical instrument (2000)that is configured and operable substantially similar to instrument (10)except for the differences discussed below. Instrument (2000) of thisexample comprises a handle assembly (2020), a shaft assembly (2030), andan end effector (2040). Handle assembly (2020) includes a body (2022)that defines a pistol grip (2024). A trigger (2028) is pivotally coupledwith body (2022) such that trigger (2028) is pivotable toward and awayfrom pistol grip (2024). An articulation and closure actuation assembly(2100) is slidably coupled with handle assembly (2020) as will bedescribed in greater detail below. It should be understood that handleassembly (2020) may also include a transducer assembly like transducerassembly (12), buttons like buttons (26), and/or various other featuresas described above with respect to handle assembly (20).

Shaft assembly (2030) of the present example comprises a proximal outersheath (2032), a distal outer sheath (2033), an inner tubular body(2230), and a flex housing (2232). It should be understood that proximalouter sheath (2032) is shown in cross-section in FIGS. 51 and 53 toreveal internal components of shaft assembly (2030). Shaft assembly(2030) further includes an articulation section (2130), which enablesend effector (2040) to be deflected laterally away from the longitudinalaxis of the proximal portion of shaft assembly (2030). Proximal outersheath (2032) distally terminates at the proximal end of articulationsection (2130). Distal outer sheath (2033) proximally terminates at thedistal end of articulation section (2130). Articulation section (2130)is thus longitudinally interposed between outer sheaths (2032, 2033)Inner tubular body (2230) also distally terminates at the proximal endof articulation section (2130). Flex housing (2232) extends along thelength of articulation section (2130). Flex housing (2232) islongitudinally secured relative to inner tubular body (2230), which isfurther longitudinally secured relative to handle assembly (2020). Flexhousing (2232) is thus longitudinally grounded relative to handleassembly (2020), though flex housing (2232) is still configured to bendin lateral deflection during articulation. In some versions, flexhousing (2232) is configured similar to the combination of ribbed bodyportions (132, 134) described above.

Shaft assembly (2030) of the present example further includes a pair ofarticulation bands (2140, 2142). The distal ends of articulation bands(2140, 2142) are secured to distal outer sheath (2033). The proximalends of articulation bands (2140, 2142) are coupled with articulationand closure actuation assembly (2100), as will be described in greaterdetail below. Articulation bands (2140, 2142) pass through a spacedefined between inner tubular body (2230) and proximal outer sheath(2032). A set of retention collars (133) are positioned aboutarticulation bands (2140, 2142) in articulation section (2130).Articulation bands (2140, 2142) are operable to actuate articulationsection (2130), to thereby deflect end effector (2040) laterally to anarticulated position. In particular, articulation bands (2140, 2142)translate in an opposing fashion to create and apply a moment to distalouter sheath (2033), thereby providing articulation of articulationsection (2130) and end effector (2040), similar to bands (140, 142)described above. It should therefore be understood that end effector(2040) will deflect laterally in the direction of whichever articulationband (2140, 2142) is moving proximally; while the other articulationband (2140, 2142) moves distally.

End effector (2040) of the present example comprises a clamp arm (2044)and an ultrasonic blade (2160). Ultrasonic blade (2160) is formed at thedistal end of a waveguide (2162). In the present example, waveguide(2162) is configured and operable identically to waveguide (180)described above, such that waveguide (2162) is configured to bend witharticulation section (2130) to achieve an articulated state. Clamp arm(2044) is operable to pivot toward and away from ultrasonic blade(2160), to thereby capture and compress tissue against ultrasonic blade(2160). In particular, one portion of clamp arm (2044) is pivotallycoupled with the distal end of flex housing (2232) (or some componentthat is longitudinally grounded to flex housing (2232)). Another portionof clamp arm (2044) is pivotally coupled with distal outer sheath(2033). Distal outer sheath (2033) is operable to translatelongitudinally relative to flex housing (2232) and the other componentsof shaft assembly (2030) that are longitudinally grounded relative tohandle assembly (2022). It should therefore be understood that clamp arm(2044) will pivot relative to blade (2160) in response to longitudinaltranslation of distal outer sheath (2033) relative to flex housing(2232) and the other components of shaft assembly (2030) that arelongitudinally grounded relative to handle assembly (2022).

Articulation and closure actuation assembly (2100) of the presentexample comprises a housing (2110) and a control knob (2126), which isrotatable relative to housing (2110). As best seen in FIGS. 52-53, wherehousing (2110) is shown in cross-section, a pinion gear (2122) isunitarily secured to control knob (2126), such that pinion gear (2122)rotates unitarily with control knob (2126) relative to housing (2110).Intermediate gears (2124, 2126) are positioned on opposite sides ofpinion gear (2122) and mesh with pinion gear (2122), such thatintermediate gears (2124) rotate in response to rotation of control knob(2126) and pinion gear (2122). As shown in FIG. 52, intermediate gear(2124) extends vertically to mesh with a rack (2240) of articulationband (2140), providing a rack and pinion relationship betweenintermediate gear (2124) and articulation band (2140). Thus, whenintermediate gear (2124) rotates, articulation band (2140) translateslongitudinally. Articulation band (2140) will therefore translatelongitudinally in response to rotation of control knob (2126). While notshown, intermediate gear (2126) meshes with a rack of articulation band(2142) in a similar fashion. Articulation bands (2140, 2142) will thustranslate longitudinally in an opposing fashion in response to rotationof control knob (2126). It should therefore be understood thatarticulation section (2130) will bend to deflect end effector (2040) ina first direction when control knob (2126) is rotated in a firstdirection; and will bend to deflect end effector (2040) in a seconddirection when control knob (2126) is rotated in a second direction. Insome versions, knob (2126) is oriented to extend along a plane that isparallel with the longitudinal axis of shaft assembly (2030) whenarticulation section (213) is straight; and obliquely relative to thelongitudinal axis of shaft assembly (2030) when articulation section(213) is bent, such that control knob (2126) provides visual feedbackindicating the state of articulation.

As noted above, articulation and closure actuation assembly (2100) isconfigured to slide longitudinally relative to handle assembly (2020).Articulation and closure actuation assembly (2100) is pivotally coupledwith trigger (2028) via a link (2090). In particular, one end of link(2090) is pivotally coupled with the underside of housing (2110) andanother end of link (2090) is pivotally coupled with the upper end oftrigger (2028). Thus, as trigger (2028) is pivoted toward pistol grip(2024), link (2090) drives articulation and closure actuation assembly(2100) distally relative to handle assembly (2020). As trigger (2028) ispivoted back away from pistol grip (2024), link (2090) drivesarticulation and closure actuation assembly (2100) proximally relativeto handle assembly (2020). When articulation and closure actuationassembly (2100) translates relative to handle assembly (2020),intermediate gears (2124, 2126) drive articulation bands (2140, 2142)longitudinally together in the same direction simultaneously. Whenarticulation bands (2140, 2142) translate longitudinally together in thesame direction simultaneously, articulation bands (2140, 2142) drivedistal outer sheath (2033) longitudinally. Such longitudinal motion ofdistal outer sheath (2033) actuates clamp arm (2044) as described above.It should therefore be understood that, as trigger (2028) is pivotedtoward pistol grip (2024), clamp arm (2044) is driven toward blade(2160) via link (2090), articulation and closure actuation assembly(2100), articulation bands (2140, 2142), and distal outer sheath (2033).Likewise, as trigger (2028) is pivoted away from pistol grip (2024),clamp arm (2044) is driven away from blade (2160) via link (2090),articulation and closure actuation assembly (2100), articulation bands(2140, 2142), and distal outer sheath (2033).

It should be understood that articulation and closure actuation assembly(2100) may include one or more features that are operable to selectivelylock the straight/articulation state of articulation section (2130) orat least resist a change in the straight/articulation state ofarticulation section (2130). By way of example only, such resistance maybe provided through friction, detent features, etc. Other suitable waysin which articulation and closure actuation assembly (2100) mayselectively lock the straight/articulation state of articulation section(2130) or at least resist a change in the straight/articulation state ofarticulation section (2130) will be apparent to those of ordinary skillin the art in view of the teachings herein.

VI. EXEMPLARY ULTRASONIC SURGICAL INSTRUMENT WITH MOTORIZED ARTICULATION

The above examples are discussed in the context of manual control ofarticulation in a shaft assembly. However, it should also be understoodthat articulation may be motorized. For instance, FIG. 54 shows anexemplary instrument (3010) that is in many ways similar to instrument(10) described above. Instrument (3010) of this example includes ahandle assembly (3020), a shaft assembly (30), and an end effector (40).Handle assembly (3020) comprises a body (3022) including a pistol grip(3028) and a pair of buttons (3026). Handle assembly (3020) alsoincludes a trigger (3028) that is pivotable toward and away from pistolgrip (3024). End effector (40) includes an ultrasonic blade (160) and apivoting clamp arm (44). Clamp arm (44) is coupled with trigger (3028)such that clamp arm (44) is pivotable toward ultrasonic blade (160) inresponse to pivoting of trigger (3028) toward pistol grip (3024); andsuch that clamp arm (44) is pivotable away from ultrasonic blade (160)in response to pivoting of trigger (3028) away from pistol grip (3024).

An ultrasonic transducer assembly (12) extends proximally from body(3022) of handle assembly (3020). Transducer assembly (12) is coupledwith a generator (16) via a cable (14), such that transducer assembly(12) receives electrical power from generator (16). Piezoelectricelements in transducer assembly (12) convert that electrical power intoultrasonic vibrations. Generator (16) may include a power source andcontrol module that is configured to provide a power profile totransducer assembly (12) that is particularly suited for the generationof ultrasonic vibrations through transducer assembly (12).

Shaft assembly (30) of the present example extends distally from handleassembly (3020). Shaft assembly (30) includes an articulation section(130), which is located at a distal portion of shaft assembly (30), withend effector (40) being located distal to articulation section (130). Aknob (3031) is secured to a proximal portion of proximal outer sheath(32). Knob (3031) is rotatable relative to body (3022), such that shaftassembly (30) is rotatable about a longitudinal axis relative to handleassembly (3020). Such rotation may provide rotation of end effector(40), articulation section (130), and shaft assembly (30) unitarily. Ofcourse, rotatable features may simply be omitted if desired.Articulation section (130) is operable to selectively position endeffector (40) at various lateral deflection angles relative to alongitudinal axis defined by outer sheath (32). Articulation section(130) may take a variety of forms, including but not limited to any ofthe forms described herein.

It should be understood that all of the above described features ofinstrument (3010) are substantially identical to the same features ofinstrument (10), except for the differences described below. Inparticular, instrument (3010) of this example lacks manually operatedarticulation control assembly (100). Instead, instrument (3010) includesa motor (3100) that is coupled with articulation section (130) to drivearticulation section (130) in a motorized fashion. Various suitable waysin which motor (3100) may be coupled with articulation section (130) todrive articulation section (130) in a motorized fashion will be apparentto those of ordinary skill in the art in view of the teachings herein. Auser input feature (3200) is in communication with motor (3100) and isoperable to selectively activate motor (3100) in response to user input.Various suitable forms that user input feature (3200) may take will beapparent to those of ordinary skill in the art in view of the teachingsherein. It should also be understood that more than one user inputfeature (3200) may be provided (e.g., one user input feature (3200) foreach direction of articulation, etc.).

In some versions, motor (3100) receives power from an external source(e.g., generator (16), etc.) via cable (14). In some other versions,motor (3100) receives power from an internal source (e.g., one or morebatteries or other portable power sources in body (3022) of handleassembly (3020), etc.). It should also be understood that motor (3100)may be located at any suitable position within body (3022) of handleassembly (3020). Alternatively, motor (3100) may be located external tobody (3022). Other suitable ways in which motor (3100) may beincorporated in instrument (3010) to drive articulation section (130)will be apparent to those of ordinary skill in the art in view of theteachings herein.

While instrument (3010) is described above as providing motorizeddriving of articulation section (130), it should be understood thatinstrument (3010) may instead incorporate any of the other articulationsections described herein. In other words, any of the articulationsections described herein may be driven in a motorized fashion.

VII. EXEMPLARY ULTRASONIC SURGICAL INSTRUMENT WITH RESTRICTEDARTICULATION

In some instances, it may be desirable to restrict the articulationangle of waveguide (180). For instance, if waveguide (180) isarticulated from the longitudinal axis defined by proximal outer sheath(32) at too steep an angle, waveguide (180) could permanently deformleading to undesirable effects. Restricting the maximum articulation ofwaveguide (180) may therefore help maintain the structural integrity ofwaveguide (180). A merely illustrative example of how the articulationangle may be restricted will be described in greater detail below.

A. Exemplary End Effector and Acoustic Drivetrain

FIG. 55A illustrates an exemplary shaft assembly (4300) and an exemplaryend effector (4340). Shaft assembly (4300) and end effector (4340) canbe utilized in instrument (10), substituting for shaft assembly (30) andend effector (40). End effector (4340) is substantially similar to endeffector (40). End effector (4340) includes an ultrasonic blade (4260)and a pivoting clamp arm (4344). Claim arm (4344) includes a clamp pad(4346) that is secured to the underside of clamp arm (4344), facingultrasonic blade (4260). Clamp pad (4346) may comprisepolytetrafluoroethylene (PTFE) and/or any other suitable material(s).

Clamp arm (4344) is pivotally secured to a distally projecting tongue(4343) of an upper distal shaft element (4272), which is fixedly securedwithin a distal portion of a distal outer sheath (4333). Lower distalshaft element (4270) is slidably disposed within the distal portion ofdistal outer sheath (4333). Trigger (28) is operable to translate lowerdistal shaft element (4270) along a path that is parallel to thelongitudinal axis defined by distal outer sheath (4333). Specifically,trigger (28) can translate lower distal shaft element (4272) proximallywhen trigger (28) is pivoted toward pistol grip (24) and distally whentrigger (28) is pivoted away from pistol grip (24). A pair or arms(4256) extend transversely from clamp arm (4344) and are pivotallysecured to lower distal shaft element (4270). Therefore, clamp arm(4344) is coupled with trigger (28) such that clamp arm (4344) ispivotable toward ultrasonic blade (4260) in response to pivoting oftrigger (28) toward pistol grip (24); and such that clamp arm (4344) ispivotable away from ultrasonic blade (4260) in response to pivoting oftrigger (28) away from pistol grip (24). Various suitable ways in whichclamp arm (4344) may be coupled with trigger (28) will be apparent tothose of ordinary skill in the art in view of the teachings herein. Insome versions, one or more resilient members are used to bias clamp arm(4344) and/or trigger (28) to the open position shown in FIG. 55A. Drivefeatures enabling trigger (28) to close clamp arm (4344) are the samefor the drive features described above enabling trigger (28) to closeclamp arm (44).

Blade (4260) of the present example is operable to vibrate at ultrasonicfrequencies in order to effectively cut through and seal tissue,particularly when the tissue is being compressed between clamp pad(4346) and blade (4260). Blade (4260) is positioned at the distal end ofan acoustic drivetrain. This acoustic drivetrain includes transducerassembly (12) and an acoustic waveguide (4280). Acoustic waveguide(4280) comprises a flexible portion (4266). Transducer assembly (12)includes a set of piezoelectric discs (not shown) located proximal to ahorn (not shown) of waveguide (4280). The piezoelectric discs areoperable to convert electrical power into ultrasonic vibrations, whichare then transmitted along waveguide (4280), including flexible portion(4266) of waveguide (4280) to blade (4260) in accordance with knownconfigurations and techniques. By way of example only, this portion ofthe acoustic drivetrain may be configured in accordance with variousteachings of various references that are cited herein.

As best seen in FIG. 56, flexible portion (4266) of waveguide (4280)includes a distal flange (4236), a proximal flange (4238), and anarrowed section (4267) located between flanges (4236, 4238). In thepresent example, flanges (4236, 4238) are located at positionscorresponding to nodes associated with resonant ultrasonic vibrationscommunicated through flexible portion (4266) of waveguide (4280).Narrowed section (4267) is configured to allow flexible portion (4266)of waveguide (4280) to flex without significantly affecting the abilityof flexible portion (4266) of waveguide (4280) to transmit ultrasonicvibrations. By way of example only, narrowed section (4267) may beconfigured in accordance with one or more teachings of U.S. Pub. No.2014/0005701, issued as U.S. Pat. No. 9,393,037 on Jul. 19, 2016, and/orU.S. Pub. No. 2014/0114334, issued as U.S. Pat. No. 9,095,367 on Aug. 4,2015, the disclosures of which are incorporated by reference herein. Itshould be understood that waveguide (4280) may be configured to amplifymechanical vibrations transmitted through waveguide (4280). Furthermore,waveguide (4280) may include features operable to control the gain ofthe longitudinal vibrations along waveguide (4280) and/or features totune waveguide (4280) to the resonant frequency of the system. Varioussuitable ways in which waveguide (4280) may be mechanically andacoustically coupled with transducer assembly (12) will be apparent tothose of ordinary skill in the art in view of the teachings herein.

In the present example, the distal end of blade (4260) is located at aposition corresponding to an anti-node associated with resonantultrasonic vibrations communicated through flexible portion (4266) ofwaveguide (4280), in order to tune the acoustic assembly to a preferredresonant frequency f_(o) when the acoustic assembly is not loaded bytissue. When transducer assembly (12) is energized, the distal end ofblade (4260) is configured to move longitudinally in the range of, forexample, approximately 10 to 500 microns peak-to-peak, and in someinstances in the range of about 20 to about 200 microns at apredetermined vibratory frequency f_(o) of, for example, 55.5 kHz. Whentransducer assembly (12) of the present example is activated, thesemechanical oscillations are transmitted through waveguide (4280) toreach blade (4260), thereby providing oscillation of blade (4260) at theresonant ultrasonic frequency. Thus, when tissue is secured betweenblade (4260) and clamp pad (4346), the ultrasonic oscillation of blade(4260) may simultaneously sever the tissue and denature the proteins inadjacent tissue cells, thereby providing a coagulative effect withrelatively little thermal spread. In some versions, an electricalcurrent may also be provided through blade (4260) and clamp arm (4344)to also cauterize the tissue. While some configurations for an acoustictransmission assembly and transducer assembly (12) have been described,still other suitable configurations for an acoustic transmissionassembly and transducer assembly (12) will be apparent to one orordinary skill in the art in view of the teachings herein. Similarly,other suitable configurations for end effector (4340) will be apparentto those of ordinary skill in the art in view of the teachings herein.

B. Exemplary Shaft Assembly and Alternative Articulation Section

When incorporated into instrument (10) described above, shaft assembly(4300) of the present example would extend distally from handle assembly(20). As shown in FIGS. 55A-56, shaft assembly (4300) includes distalouter sheath (4333) and a proximal outer sheath (4332) that enclosesclamp arm (4344) drive features and the above-described acoustictransmission features. Shaft assembly (4300) further includes anarticulation section (4230), which is located at a distal portion ofshaft assembly (4300), with end effector (4340) being located distal toarticulation section (4230).

Similar to articulation section (130), articulation section (4230) isoperable to selectively position end effector (4340) at various lateraldeflection angles relative to a longitudinal axis defined by outersheath (4332). Articulation section (4230) may take a variety of forms.By way of example only, articulation section (4230) may be configured inaccordance with one or more teachings of U.S. Pub. No. 2012/0078247,issued as U.S. Pat. No. 9,402,682 on Aug. 2, 2016. the disclosure ofwhich is incorporated by reference herein. As another merelyillustrative example, articulation section (4230) may be configured inaccordance with one or more teachings of U.S. Pub. No. 2014/0005701,issued as U.S. Pat. No. 9,393,037 on Jul. 19, 2016, and/or U.S. Pub. No.2014/0114334, issued as U.S. Pat. No. 9,095,367 on Aug. 4, 2015, thedisclosures of which are incorporated by reference herein. Various othersuitable forms that articulation section (4230) may take will beapparent to those of ordinary skill in the art in view of the teachingsherein.

As illustrated in FIGS. 55A-56, articulation section (4230) of thisexample comprises a set of three retention collars (4500), a distalmating feature (4332A) of proximal outer sheath (4332), a proximalmating feature (4333A) of distal outer sheath (4333), a set of bodyportions (4700, 4800, 4900), a flexible locking feature (4600), and apair of articulation bands (4440, 4442) extending along channels(4235A-C) defined by translation members (4261, 4262), proximal bodyportion (4900) and distal body portion (4800). Distal mating feature(4332A) and proximal mating feature (4333A) both comprise insert holes(4334).

As illustrated in FIGS. 57-58, each retention collar (4500) comprises afirst angled contact surface (4501), a second angled contact surface(4525), a circular segment surface (4505), and a pair of flattenedsurfaces (4510) extending inwardly from circular segment surface (4505).Flattened surfaces (4510) define a pathway (4520) and a pair of insertholes (4515). First angled contact surface (4501) is configured tocontact a complementary first angled contact surface (4501) of anotherretention collar (4500). Distal mating feature (4332A) of proximal outersheath (4332) and proximal mating feature (4333A) of distal outer sheath(4333) are substantially similar to retention collar (4500), but withoutfirst angled contact surface (4501) and second angled contact surface(4525). As best seen in FIG. 68, distal mating feature (4332A) andproximal mating feature (4333A) each have a first angled contact surface(4335) that complements first angled contact surfaces (4501) ofretention collars (4501).

As illustrated in FIGS. 59-60, flexible locking feature (4600) comprisesa connecting spine (4630), pairs of resilient legs (4625) extending fromconnecting spine (4630), tabs (4620) located at the termination of eachresilient leg (4625), and a rib (4605) running longitudinally alongconnecting spine (4630) and in between each pair of resilient legs(4625). Each tab (4625) further comprises an angled surface (4610) and atransverse surface (4615).

As illustrated in FIGS. 62-63, each intermediate body portion (4700)comprises an arched base (4705), an articulation band ledge (4710), atab window (4715), an exterior surface (4735), an interior surface(4750), a leg channel (4740), and a cable channel (4774). Tab window(4715) is defined by transverse walls (4725), tab floor (4730), and tabceiling (4720). Leg channel (4740) is defined by interior tab contactsurface (4745) and transverse walls (4725). Articulation band ledge(4710) extends transversely from exterior surface and terminates atarched base (4705). Each articulation band ledge (4710) is configured toat least partially support or otherwise accommodate a correspondingarticulation band (4440, 4442) between second channel for articulationband (4235B) and third channel for articulation band (4235C). Legchannel (4740) is configured and dimensioned to act as a guide forinsertion of resilient legs (4625) of flexible locking feature (4600).Cable channel (4774) provides a linear path for a drive feature (e.g.,cable (174) as described above) to communicate with trigger (28) inorder to move clamp arm (4344).

FIGS. 64-65 illustrate distal body portion (8400). Similarly tointermediate body portion (4700), distal body portion (4800) comprisesan arched base (4805), an articulation band ledge (4810), a tab window(4815), an exterior surface (4835), an interior surface (4850), a legchannel (4840), and a cable channel (4874). Tab window (4815) is definedby transverse walls (4825), tab floor (4830), and tab ceiling (4820).Leg channel (4840) is defined by interior tab contact surface (4845) andtransverse walls (4825).

All of the features mentioned above for the distal body portion (4800)are substantially the same as their counterparts of intermediate bodyportion (4700). However, distal body portion (4800) additionallycomprises a resilient tab (4885), a mating feature for articulation band(4890), a narrowed pathway (4895), and third channel for articulationband (4235C). Resilient tab (4885) further comprises a transversesurface (4875) and an extending surface (4850). Articulation band ledge(4810) extends transversely from exterior surface and terminates atarched base (4805). Each articulation band ledge (4810) is configured toat least partially support or otherwise accommodate a correspondingarticulation band (4440, 4442) between second channel for articulationband (4235B) and third channel for articulation band (4235C). Legchannel (4840) is configured and dimensioned to act as a guide forinsertion of resilient legs (4625) of flexible locking feature (4600).Cable channel (4874) provides a linear path for a drive feature (e.g.,cable (174) as described above) to communicate with trigger (28) inorder to move clamp arm (4344).

FIG. 66 illustrates proximal body portion (4900). Similarly tointermediate body portion (4700), proximal body portion (4900) comprisesan arched base (4905), an articulation band ledge (4910), a tab window(4915), an exterior surface (4935), an interior surface (4950), a legchannel (4940), and a cable channel (4974). Tab window (4915) is definedby transverse walls (4925), tab floor (4930), and tab ceiling (4920).Leg channel (4940) is defined by interior tab contact surface (4945) andtransverse walls (4925).

All of the features mentioned above for the proximal body portion (4900)are substantially the same as their counterparts for both intermediatebody portions (4700) and distal body portion (4900). However, proximalbody portion (4900) additionally comprises second channel (4235B) forarticulation band (4440, 4442). Articulation band ledge (4910) extendstransversely from exterior surface and terminates at arched base (4905).Each articulation band ledge (4910) is configured to at least partiallysupport or otherwise accommodate a corresponding articulation band(4440, 4442) as articulation band ledge (4910) helps partially definesecond channel (4235B) for articulation band (4440, 4442). Leg channel(4940) is configured and dimensioned to act as a guide for insertion ofresilient legs (4625) of flexible locking feature (4600). Cable channel(4974) provides a linear path for a drive feature (e.g., cable (174) asdescribed above) to communicate with trigger (28) in order to move clamparm (4344).

FIGS. 55A-56 illustrate the assembly of articulation section (4230). Asillustrated in FIGS. 55D, 56, and 61, body portions (4700, 4800, 4900)are longitudinally aligned with one another between flanges (4236,4238). In the present example, body portions (4700, 4800, 4900) areformed as discrete pieces positioned adjacent to each other, therebypromoting lateral flexing of articulation section (4230). Alternatively,body portions (4700, 4800, 4900) may be joined together by living hingesor any other structures that provide lateral flexing of articulationsection (4230) as will be apparent to those of ordinary skill in the artin view of the teachings herein. In the current example, there is oneproximal body portion (4900), three intermediate body portions (4700),and one distal body portion (4800). Of course, any suitable number ofintermediate body portions (4700) may be provided.

As illustrated in FIGS. 55C and 56, body portions (4700, 4800, 4900)also partially define a channel (4235B, 4235C) that is configured toreceive articulation band (4440) while allowing articulation band (4440)to slide relative to proximal body portion (4900) and intermediate bodyportions (4700). Unlike the previously mentioned articulation section(130), articulation bands (4440, 4442) are fixed to distal body portion(4800) rather than distal flange (4236). Because of this, distal flange(4236) does not require features, such as flats (192) to accommodatearticulation bands (4440, 4442). Additionally, the shortened distance ofarticulation bands (4440, 4442) provides a user with greater control ofarticulation. During longitudinal deflection, more force is requiredfrom the shortened length of articulation bands (4440, 4442) to providean equivalent moment as provided by longer articulation bands (140,142). Therefore, a user has more tolerance control of the articulationangle due to the greater force required with shorter articulation bands(4440, 4442) than longer articulation bands (140, 142).

As illustrated in FIG. 55B, Proximal body portion (4900) is locatedwithin distal mating feature (4332A) of proximal outer sheath (4332)while distal body portion (4800) is located within proximal matingfeature (4333A) of distal outer sheath (4333). Intermediate bodyportions (4700) are located in between proximal outer sheath (4332) anddistal outer sheath (4333). More specifically, insert holes (4515) arelocated directly above leg channels (4740, 4840, 4940) of body portions(4700, 4800, 4900) in order to provide an insertion pathway forresilient legs (4625) of flexible locking feature (4600). In otherwords, retention collars (4500) are located at longitudinal positionscorresponding to intermediate body portions (4700) while proximal matingfeature (4333A) and distal mating feature (4332A) are located atlongitudinal positions corresponding to distal body portion (4800) andproximal body portion (4900) respectively. Additionally, resilient tab(4885) of distal body portion (4800) is sized to fit within couplingfeatures (4338) of distal outer sheath (4333), thereby ensuring distalbody portion (4800) is fixed relative to distal outer sheath (4333). Ofcourse, a similar feature can be added to proximal body portion (4900)to ensure sufficient attachment to proximal outer sheath (4332).

As illustrated in FIGS. 55A and 67-68, flexible locking feature (4600)is inserted into distal mating feature (4332A), retention collars(4500), proximal mating feature (4333A), proximal body portion (4900),intermediate body portions (4700), and distal body portion (4800).Flexible locking feature (4600) unitarily couples distal mating feature(4332A), retention rings (4500), and proximal mating feature (4333A)with proximal body portion (4900), intermediate body portions (4700),and distal body portion (4800) respectively. This coupling can be seenin greater detail in FIG. 67. When tabs (4620) of resilient legs (4625)are first inserted into insert holes (4515), resilient legs (4625) mustbe compressed inwardly to accommodate transverse surface (4615). Contactbetween interior tab contact surface (4745) and tab (4620) keepsresilient legs (4625) in a compressed position. Once transverse surface(4615) passes interior tab contact surface (4745) to tab window (4715),resilient legs (4625) transition from a compressed state to an originalstate substantially parallel with each other. Tab (4620) then entersthrough tab window (4715). At this point, flexible locking member (4600)is locked in place through a snap fit due to overlapping dimensions oftab ceiling (4720) and transverse surface (4615). Rib (4605) is nowlocated within pathway (4520) of retention collar (4500). No object isin contact with the narrow section of waveguide (4267).

Due to the insertion of resilient legs (4625) into insert holes (4515)and leg channel (4740), retention collar (4500) is fixed along thelongitudinal axis relative to intermediate body portions (4700).Similarly, due to the insertion of resilient legs (4625) into insertholes (4334) and leg channel (4840, 4940), proximal body portion (4900)and distal body portion (4800) are fixed along the longitudinal axisrelative to distal mating feature (4332A) and proximal mating feature(4333A).

As mentioned before, the distal ends of articulation bands (4440, 4442)are unitarily secured to distal body portion (4800) via mating featurefor articulation band (4890). When articulation bands (4440, 4442)translate longitudinally in an opposing fashion (e.g., one articulationband (4440) translating distally while the other articulation band(4442) simultaneously translates proximally), this will causearticulation section (4330) to bend due to creation of a moment appliedto a distal end of distal outer sheath (4333) via upper distal shaftelement (4272). The force provided by translation of articulation bands(4440, 4442) is communicated to distal body portion (4800) via a matingfeature for articulation band (4890), which in turn is communicated todistal outer sheath (4333) via the connection of resilient tab (4885) ofdistal body portion (4800) and coupling feature (4338) of distal outersheath (4333).

Distal outer sheath (4333) is secured to waveguide (4280) at distalflange (4236), which is located at a position corresponding a nodeassociated with resonant ultrasonic vibrations communicated throughwaveguide (4280). Therefore, the force required to bend waveguide (4280)for articulation is still communicated to waveguide (4280) at the nodalposition of distal flange (4236), similar to waveguide (180). The bendthereby laterally deflects end effector (4340) away from thelongitudinal axis of shaft assembly (4300) from a straight configurationas shown in FIGS. 68-69A to an articulated configuration as shown inFIG. 69B. In particular, end effector (4340) will be articulated towardthe articulation band (4440, 4442) that is being pulled proximally.During such articulation, the other articulation band (4440, 4442) maybe pulled distally by upper distal shaft element (4272). Alternatively,the other articulation band (4440, 4442) may be driven distally by anarticulation control.

Flexible locking feature (4600) and narrowed section (4267) aresufficiently flexible to accommodate the above-described articulation ofend effector (4340). Intermediate body portions (4700) and retentioncollars (4500) are able to articulate by moving relative to each otherdue to force provided by flexible locking feature (4600). Furthermore,flexible acoustic waveguide (4266) is configured to effectivelycommunicate ultrasonic vibrations from waveguide (4280) to blade (4260)even when articulation section (4230) is in an articulated state asshown in FIG. 69B.

However, the flexible locking feature (4600) and the narrowed section(4267) are limited in articulation due to the geometry of retentioncollars (4500) and flexible locking element (4600). As best illustratedin FIG. 68, second angled contact surface (4525) of retention collar(4500) is dimensioned to allow a certain amount of clearance betweenarticulation between rib (4605) of flexible locking member (4600) andretention collar (4500), thereby permitting articulation.

As best shown in FIG. 69A-B, first angled contact surface (4501) of oneretention collar (4500) is dimensioned to abut against first angledcontact surface (4501) of a second retention collar (4500), therebyproviding a stop to limit articulation at a predetermined angle. As seenin FIG. 69A, angles X and Z are formed between first angled contactsurfaces (4501) in an unarticulated position. While in this example, theangles X and Z are substantially similar, there is no requirement thatthe angles formed by first angled contact surfaces (4501) be identical.Alternatively, X could be twice the amount as Z, or X could be 0 degreesand Z could determine the entire articulation range. FIG. 69B showsarticulation section (4230) in a maximum articulated state. First angledcontact surfaces (4501) on one side of retention collars (4500) lockeach other while the opposite side of first angled contact surfaces(4501) are further apart. Accordingly, the maximum articulation islimited to theta. In the present example, the maximum articulation angleis 30°.

Similar to articulation feature (130), articulation bands (4440, 4442)are laterally interposed within channels (4235B, 4235C) betweenretention collars (4500) and intermediate body portions (4700).Retention collars (4500) are configured to keep articulation bands(4440, 4442) in a parallel relationship with each other, particularlywhen articulation section (4330) is in a bent configuration (e.g.,similar to the configuration shown in FIG. 69B). In other words, whenarticulation band (4440) is on the inner diameter of a curvedconfiguration presented by a bent articulation section (4330), retentioncollars (4500) may retain articulation band (4440) such thatarticulation band (4440) follows a curved path that complements thecurved path followed by articulation band (4442). It should beunderstood that channels (4235B, 4235C) are sized to accommodaterespective articulation bands (4440, 4442) in such a way thatarticulation bands (4440, 4442) may still freely slide througharticulation section (4330), even with retention collars (4500) beingsecured to intermediate body portions (4700). It should also beunderstood that retention collars (4500) may be secured to body portions(4700, 4800, 4900) in various ways, including but not limited tointerference fitting, adhesives, welding, etc.

VIII. EXEMPLARY DISTAL FLANGE WITH CRUSH RIBS

In some instances it may be desirable for distal outer sheath (33, 4333)to be secured against distal flange (136, 4236) while maintainingminimal contact with distal flange (136, 4236). Minimal contact betweendistal outer sheath (33, 4333) and distal flange (136, 4236) may bedesirable in order to limit the amount energy absorbed by outer sheath(33, 4333) in order to maintain a structurally secured connectionbetween distal outer sheath (33, 4333) and distal flange (136, 4236). Tothat end, FIGS. 70-71 show an exemplary distal node bumper (4400) thatmay be used to secure distal outer sheath (33, 4333) to distal flange(136, 4236).

Distal node bumper (4400) of the present example is formed of anelastomeric material (e.g., silicone, etc.) and comprises a pair offlats (4420), a slot (4405), an outer surface (4415), crush ribs (4410)longitudinally disposed on surface (4415), and a face (4425). Flats(4420) complement flats of distal flange (136), thereby ensuring asecure connection between distal node (136) and distal node bumper(4400). Slot (4405) allows space for cable (174) to pass through distalnode bumper (4400). Crush ribs (4410) are resilient, but compress withindistal outer sheath (33) in order to provide a secure connection betweendistal flange (136) and distal outer sheath (33). Crush ribs (4410) alsoprovide limited contact between distal flange (136) and distal outersheath (33), thereby transferring minimal ultrasonic vibration energy todistal outer sheath (33), helping maintain a structurally securedconnection between distal outer sheath (33) and distal flange (136).

IX. WAVEGUIDE WITH KEYHOLE CROSS SECTIONAL PROFILE

In some instances, articulation of waveguide (180, 4280) might lead tovaried location of interaction between clamp pad (46, 4346) and blade(60, 4260) about the longitudinal axis when clamp pad (46, 4346) is in aclosed position. For instance, when the articulation section (130, 4230)is in a non-articulated state, and clamp pad (46, 4346) is pivotedtoward and away from blade (60, 4260), clamp pad (46, 4346) may traversea vertically oriented path that is on-plane with a vertical plane thatlaterally bisects blade (60, 4260).

In some instances when the articulation section (130, 4320) is in anarticulated state, and clamp pad (46, 4346) is pivoted toward and awayfrom blade (60, 4260), clamp pad (46, 4346) may traverse an obliquelyoriented path that is off-plane with a vertical plane that laterallybisects blade (60, 4260). In other words, the path that is traversed byclamp pad (46, 4346) may be obliquely oriented relative to a verticalplane that laterally bisects blade (60, 4260). This may be caused by atolerance stack in the shaft assembly (30, 4300) and/or due to otherfactors. If this occurs to a blade that has a radius that varies alongthe surface range at which clamp pad (46, 4346) may compress tissue,such off-plane closure of clamp pad (34, 4346) may result in acompression force profile on the tissue that differs from thecompression force profile that would be encountered by the tissue whenclamp pad (46, 4346) is closed on-plane with articulation section (130,4230) in a non-articulated state. In other words, the compression forceprofile on the tissue may vary based on whether articulation section(130, 4230) in an articulated state or a non-articulated state. Forinstance, such variation may lead to different times required to cutand/or seal tissue (e.g., by denaturing proteins in tissue cells). Thisinconsistency may cause an operator to expose blade (60, 4260) to directcontact with clamp pad (46, 4346) for a longer amount of time thandesired. Direct contact between blade (60, 4260) and clamp pad (46,4346) could lead to higher operating temperatures, possibly leading todeformation of blade (60, 4260) and/or clamp pad (46, 4346). It maytherefore be desirable to prevent such variance in the compression forceprofile, thereby providing an end effector that provides a moreconsistent and predictable performance.

One method of providing uniform times for cutting and/or sealing is touse a blade (5000) with a keyhole cross sectional area, as shown inFIGS. 72-74. Blade (1000) of this example comprises a clamping surface(5003), an elongated surface (5002), and a back-cutting surface (5001).Clamping surface is substantially circular in shape, with a constantradius of curvature, and with a circumference large enough to preventclamp pad (46) from clamping tissue on any other surface of blade(5000). By way of example only, the constant radius of curvature mayextend for at least 180° of the cross-sectional area of blade (5000), ormore particularly for at least 270° of the cross-sectional area of blade(5000), or more particularly for at least 320° of the cross-sectionalarea of blade (5000). Since clamping surface is substantially circularin shape, the tissue (6000) surface area exposed to blade (5000) isuniform regardless of articulation location, and regardless of whetherclamp pad (46) is on-plane or off-plane with blade (5000) duringclosure. Elongated surface (5002) is relatively thin compared toclamping surface (5003). Elongated surface (5002) also extends from thebottom of clamping surface (5003). The shape and location of elongatedsurface (5002) ensures elongated surface (5002) will not come intocontact with tissue (6000) clamped between clamp pad (46) and blade(5000). Back-cutting surface (5001) is located furthest away from clamppad (46). Back-cutting surface (5001) is operable to cut and/or sealtissue (e.g., by denaturing proteins in tissue cells) without clampingtissue beforehand. It should also be understood that back-cuttingsurface (5001) may be used to perform back-cutting on tissue.

X. EXEMPLARY ALTERNATIVE FEATURES FOR SELECTIVELY LOCKING ARTICULATIONSECTION

In some versions of instrument (10) it may be desirable to providefeatures that are configured to selectively lock articulation section(130) at a selected state of articulation. For instance, whenarticulation section (130) is in a straight configuration, it may bedesirable to lock articulation section (130) in the straightconfiguration in order to prevent inadvertent lateral deflection of endeffector (40) at articulation section (130). Similarly, whenarticulation section (130) is bent to a selected articulation angle, itmay be desirable to lock articulation section (130) at that selectedarticulation angle in order to prevent inadvertent lateral deflection ofend effector (40) way from that selected articulation angle atarticulation section (130). Various examples of features that areconfigured to selectively lock articulation section (130) at a selectedstate of articulation will be described in greater detail below. Otherexamples will be apparent to those of ordinary skill in the artaccording to the teachings herein.

A. Articulation Control Assembly with Resiliently Biased Locking Paddleon Knob

FIGS. 75-76B show an exemplary articulation control assembly (9200) thatmay be readily incorporated into instrument (10) in place ofarticulation control assembly (100). Except as otherwise describedbelow, articulation control assembly (9200) is configured and operablejust like articulation control assembly (100) described above.Articulation control assembly (9200) of this example comprises a housing(9210) and a knob (9220). Rotation of rotation knob (9220) relative tohousing (9210) causes articulation of an articulation section of a shaftassembly, such as articulation section (130) of shaft assembly (30).Articulation control assembly (9200) of this example further comprises alocking feature (9230) that is configured to selectively prevent therotation of knob (9220). It should be understood that, by preventingrotation of knob (9220), locking feature (9230) further preventsarticulation of the articulation section of the shaft assembly. Lockingfeature (9230) may be used in lieu of, or in addition to, other featuresdiscussed herein that selectively prevent rotation of knob (9220); andthat selectively lock articulation section (9130) in a particulardeflected position relative to the longitudinal axis defined by outersheath (32).

As shown in FIGS. 75-76B, locking feature (9230) of the present exampleincludes a paddle (9232), a lever member (9234), a lock arm (9236), anda spring (9238). In the present example, paddle (9232) is operablycoupled to lever member (9234) at pivot point (9238). Paddle (9232) andlever member (9234) together form an oblique angle at pivot point(9238). Pivot point (9238) provides a pivotal coupling of paddle (9232)and lever member (9234) to the underside of knob (9220). Paddle (9232)and lever member (9234) are rigidly coupled together such that thepivoting of paddle (9232) about pivot point (9238) causes lever member(9234) to rotate or pivot in the same direction about pivot point(9238). In particular, paddle (9232) and lever member (9234) arepivotable between a first position (FIG. 76A) and a second position(FIG. 76B). In the first position, paddle (9232) is oriented obliquelyrelative to a vertical plane (going into and out of the page in theviews shown in FIGS. 76A-76B) that is defined by knob (9220); whilelever member (9234) extends along the vertical plane defined by knob(9220). In the second position, paddle (9232) extends along the verticalplane defined by knob (9220); while lever member (9234) is orientedobliquely relative to the vertical plane defined by knob (9220).

Lever member (9234) is pivotably coupled to lock arm (9236). Lock arm(9236) is resiliently biased toward inner wall (9242) housing (9210) byspring (9238). In the locked configuration (FIG. 76A), lock arm (9236)positively engages housing (9210) and thereby prevents rotation of knob(9220) relative to housing (9210). Lock arm (9236) is configured totranslate along a path that is transverse to the vertical plane definedby knob (9220). In particular, lock arm (9236) translates along thispath in response to pivoting of paddle (9232) and lever member (9234)between the first and second positions as described above. By way ofexample only, the underside of knob (9220) may include a channel that issized to receive and guide lock arm (9236) in order to keep lock arm(9236) on this linear path of travel. As another merely illustrativeexample, one or more guiding features (e.g., rails, etc.), may beconfigured to receive and guide lock arm (9236) in order to keep lockarm (9236) on this linear path of travel.

In the example shown, lock arm (9236) includes a pointed end (9240) thatis configured to frictionally engage an inner wall (9242) of housing(9210). In some examples, inner wall (9242) of housing (9210) includesone or more features to enhance the positive engagement between lock arm(9236) and housing (9210). For example, inner wall (9242) of housing(9210) may include notches, splines, detents, frictional coatings,frictional surface treatments, etc., with which the lock arm (9236) mayengage. It should also be understood that pointed end (9240) may includean elastomeric material and/or any other suitable feature(s) to promotea locking relationship between pointed end (9240) and inner wall (9242)of housing (9210).

When articulation control assembly (9200) is in the configuration shownin FIG. 76A, articulation control assembly (9200) is in a locked statedue to engagement between pointed end (9240) of lock arm (9242) andinner wall (9242) of housing (9210). This locked state provides lockingof the articulation state of the articulation section of the shaftassembly, regardless of whether the articulation section is in astraight configuration or a bent configuration. In order to unlockarticulation control assembly (9200) in order to change the articulationstate of the articulation section, an operator may drive paddle (9232)from the position shown in FIG. 76A to the position shown in FIG. 76B bypinching paddle (9232) toward knob (9220). This causes paddle (9232) topivot about pivot point (9238) toward knob (9220), which in turn causespivoting of lever member (9234) in the same angular direction aboutpivot point (9238). This pivoting of lever member (9234) pulls lock arm(9236) away from inner wall (9242) of housing (9210), such that pointedend (9240) disengages inner wall (9242) of housing (9210). With pointedend (9240) disengaged from inner wall (9242) of housing (9210),articulation control assembly (9200) is in an unlocked state, such thatknob (9220) may be rotated relative to housing (9210) to change thearticulation state of the articulation section of the shaft assembly.

Once the user has reached the desired articulation state, the operatormay release paddle (9232). When the operator releases paddle (9232), theresilience of spring (9238) may return lock arm (9236), lever member(9234), and paddle (9232) back to the locked configuration (FIG. 76A).The articulation section will thus be re-locked at the adjustedarticulation state.

B. Articulation Control Assembly with Upwardly Biased Clutching Lock

FIGS. 77-78 show another exemplary articulation control assembly (9300)that may be readily incorporated into instrument (10) in place ofarticulation control assembly (100). Except as otherwise describedbelow, articulation control assembly (9300) is configured and operablejust like articulation control assembly (100) described above.Articulation control assembly (9300) of this example comprises a housing(9310) and a knob (9320). Rotation of rotation knob (9320) relative tohousing (9310) causes articulation of an articulation section of a shaftassembly, such as articulation section (130) of shaft assembly (30).Articulation control assembly (9300) of this example further comprises alocking feature (9330) that is configured to selectively prevent therotation of knob (9320). It should be understood that, by preventingrotation of knob (9320), locking feature (9330) further preventsarticulation of the articulation section of the shaft assembly. Lockingfeature (9330) may be used in lieu of, or in addition to, other featuresdiscussed herein that selectively prevent rotation of knob (9320); andthat selectively lock articulation section (130) in a particulardeflected position relative to the longitudinal axis defined by outersheath (32).

As shown in FIGS. 77-77B, locking feature (9330) of the present exampleincludes a plurality of female spline features (9332) disposed onhousing (9310), and a male spline feature (9334) coupled to knob (9320).Female spline features (9332) are more particularly defined as recessesdisposed circumferentially and presented downwardly along an annular lip(9338) (FIG. 78) that surrounds a body portion (9340) of knob (9320)(when knob is received within housing (9310)). Male spline feature(9334) includes a first portion (9334 a) that extends radially outwardlyfrom body portion (9340) and a second portion (9334 b) that extendsupwardly, perpendicular to the first portion (9334 b). While only onemale spline feature (9334) is shown, it should be understood that bodyportion (9340) may include two more male spline features (9334). Forinstance, a plurality of male spline features (9334) may be angularlyspaced along at least a portion of the perimeter of body portion (9340).It should also be understood that female spline features (9332) may beangularly spaced along any suitable angular range along thecircumference of annular lip (9338).

As shown, female and male spline members (9334, 9332) are similarlyshaped such that the female spline members (9332) are defined ascavities having shapes that complement the end (9339) of the male splinefeature (9334). FIG. 77A shows male spline feature (9334) received infemale spline feature (9332). In this state, locking feature (9330)prevents knob (9320) from rotating relative to housing (9310), therebylocking articulation section (130) in its current articulated (ornon-articulated) position relative to the longitudinal axis defined byouter sheath (32). In the present example, female spline feature (9332)and end (9339) of male spline features (9334) define pyramidal shapeswith pointed portions. In some other examples, spline features (9332,9334) are substituted with a plurality of complementary teeth arrangedin a starburst pattern. Various suitable other ways in which splinefeatures (9332, 9334) may be may be configured will be apparent to thoseof ordinary skill in the art in view of the teachings herein.

In the present example, a resilient element (9336) biases knob (9320)upwardly into a position where an end (9339) of male spline feature(9334) is received with and engages one of the female spline features(9332), thereby preventing the rotation of knob (9320) relative tohousing (9310). Resilient element (9336) may comprise a coil spring, awave spring, a leaf spring, and/or any other suitable kind of resilientfeature. In some examples, locking feature (9330) may be configured toact as a slipping clutch mechanism. That is, in some such examples, theengagement of male spline feature (9334) with one of the female splinefeatures (9332) may be overcome by a user applying sufficient rotationalforce to knob (9320); but absent such force, the engagement will sufficeto maintain the straight or articulated configuration of articulationsection (130). It should therefore be understood that the ability toselectively lock knob (9320) in a particular rotational position willprovide selective locking of articulation section (130) in a particulardeflected position relative to the longitudinal axis defined by outersheath (32).

In some other examples, the male spline feature (9334) and female splinefeatures (9332) are configured such that that it is difficult toovercome that engagement between male spline feature (9334) and femalespline features (9332) by simply providing a rotational force to knob(9320); or such that the rotational force required to overcome theengagement may cause unintended damage to one or more components of theinstrument (10). Such a configuration, where a relatively higherrotational force is required to rotate knob (9320), may be provided forthe prevention of unintended articulation as a result of inadvertentrotation of knob (9320).

In the example shown, in order to enable rotation of knob (9320), theoperator must press knob (9320) in a direction (defined by arrow(9341)), along an axis that is perpendicular to the longitudinal axis ofshaft assembly (30). In the present example, knob (9320) is pressedalong the same axis about which knob (9320) is rotated in order to drivearticulation of articulation section (130). When the user depresses knob(9320) with a sufficient force to overcome the bias of a resilientelement (9336), end (9339) of male spline feature (9334) disengages fromfemale spline feature (9332) as shown in FIG. 77B. Knob (9320) is thenfree to rotate relative to housing (9310) as the operator continues topress downwardly on knob (9320). In examples where the engagementbetween male spline feature (9334) and female spline features (9332) maybe overcome by applying sufficient rotational disengagement force toknob (9320), the rotational force required to rotate the knob (9320) inthe unlocked configuration is less than the rotational force required todisengage male spline feature (9334) from female spline feature (9332).

When the operator rotates knob (9320) while knob (9320) is in thedownward, unlocked position, such rotation of knob (9320) causes thearticulation of articulation section (130). Once the user hasarticulated articulation section (130) a desired amount (whether to orfrom an articulated state), the user may release the downward force (inthe direction of arrow (9341)) on knob (9320). Resilient element (9336)will then resiliently urge knob (9320) back to the locked configurationof FIGS. 77 and 77A, such that articulation section (130) is locked inthe adjusted articulation state relative to the longitudinal axisdefined by outer sheath (32). In some examples, the operator may need toensure the proper alignment of corresponding male spline feature (9334)and a particular female spline feature (9332) to enable the knob (9320)to return to the locked configuration. However, in some examples,locking feature (9330) may be configured to circumferentially aligncorresponding male spline feature (9334) with a circumferentiallyadjacent female spline feature (9332) to ensure a smooth transition tothe locked configuration. In other words, spline features (9332, 9334)may be configured to self-align with each other. Various suitable waysin which locking feature (9330) may be may be configured will beapparent to those of ordinary skill in the art in view of the teachingsherein.

C. Articulation Control Assembly with Downwardly Biased Clutching Lock

FIGS. 79A-81 show another exemplary articulation control assembly (9400)that may be readily incorporated into instrument (10) in place ofarticulation control assembly (100). Except as otherwise describedbelow, articulation control assembly (9400) is configured and operablejust like articulation control assembly (100) described above.Articulation control assembly (9400) of this example comprises a housing(9410) and a knob (9420). Rotation of rotation knob (9420) relative tohousing (9410) causes articulation of an articulation section of a shaftassembly, such as articulation section (130) of shaft assembly (30).Articulation control assembly (9400) of this example further comprises alocking feature (9430) that is configured to selectively prevent therotation of knob (9420). It should be understood that, by preventingrotation of knob (9420), locking feature (9430) further preventsarticulation of the articulation section of the shaft assembly. Lockingfeature (9430) may be used in lieu of, or in addition to, other featuresdiscussed herein that selectively prevent rotation of knob (9420); andthat selectively lock articulation section (130) in a particulardeflected position relative to the longitudinal axis defined by outersheath (32). Locking feature (9430) is shown in a locked configurationin FIG. 79A and an unlocked configuration in FIG. 79B.

Locking feature (9430) of the present example comprises a plurality ofmale spline features (9432) and a plurality of female spline features(9436). As best seen in FIG. 79B, male spline features (9432) extenddownwardly (direction defined by defined by arrow (9438)) from lip(9434) of knob (9420). As best seen in FIG. 80, male spline features(9432) are angularly spaced in an annular array along the underside oflip (9434). Male spline features (9432) of the present example aregenerally rectangular in shape. Alternatively, male spline features(9432) may instead have a pyramidal shape, a starburst configuration,and/or any other suitable configuration.

As best seen in FIG. 79B, female spline features (9436) compriserecesses that are formed in an upwardly facing surface (9412) of housing(9410). As best seen in FIG. 81, female spline features (9436) areangularly spaced in an annular array along upwardly facing surface(9412) with spacing that complements the spacing of male spline features(9432). Female spline features (9436) are shaped similarly to malespline features (9432) such that female spline features (9436) definegenerally rectangular recesses, and are spaced apart from one anothercircumferentially such that female spline features (9436) may receivecorrespondingly shaped and angularly spaced male spline features (9432)as shown in FIG. 79A. In the present example, there are an equal numberof male and female spline features (9432, 9436). However, in otherexamples, there may be fewer male spline features (9432) than femalespline features (9436), provided that the male spline features (9432)are configured to be received in corresponding female spline features(9436) (9 e.g., proper sizing and angular spacing). When male splinefeatures (9432) are positioned in female spline features (9436), theengagement between spline features (9432, 9436) prevents knob (9420)from rotating relative to housing (9410). Thus, when locking feature(9430) is in a locked state due to engagement between spline features(9432, 9436), locking feature (9430) locks the articulation section atits current state of articulation relative to the longitudinal axis ofthe shaft assembly.

In the present example, a pair of coil springs (9440) is operablycoupled to knob (9420) via a pair of links (9441) that resiliently biasknob (9420) downwardly (9 in the direction defined by arrow (9438)).Springs (9440) thus bias knob (9420) and male spline features (9432)into the locked position shown in FIG. 79A. Due to the engagementbetween male and female spline features (9432, 9436), knob (9420) isunable to rotate relative to housing (9410). Of course, any othersuitable kind of resilient member(s) may be used in addition to or inlieu of coil springs (9440).

In some examples, locking feature (9430) may be configured to act as aslipping clutch mechanism such that a sufficient amount of angular forceon knob (9420) causes male spline features (9432) to slip between femalespline features (9436). In some such examples, male and/or female splinefeatures (9432, 9436) may include ramped or cammed surfaces to enablethe slipping clutch action therebetween. In some such examples, theengagement of male spline features (9432) with one of the female splinefeatures (9436) may be overcome by a user applying sufficient rotationalforce to knob (9420); but absent such force, the engagement will sufficeto maintain the straight or articulated configuration of articulationsection (130). It should therefore be understood that the ability toselectively lock knob (9420) in a particular rotational position lockwill enable an operator to selectively lock articulation section (130)in a particular deflected position relative to the longitudinal axisdefined by outer sheath (32).

In the example shown, in order to enable rotation of knob (9420), theoperator must pull knob (9420) in the direction of arrow (9442) along anaxis that is perpendicular to the longitudinal axis of shaft assembly(30), into the unlocked configuration shown in FIG. 79B. In the presentexample, knob (9420) is pulled along the same axis about which knob(9420) is rotated in order to drive articulation of articulation section(130). As shown, in the unlocked configuration, male spline features(9432) are disengaged from female spline features (9436) (i.e., malespline features (9432) are spaced from female spline features (9436)).Thus, in the unlocked configuration, knob (9420) is able to rotaterelative to housing (9410) along an axis that is perpendicular to thelongitudinal axis of outer sheath (32) and cause articulation ofarticulation section (130), for example. In examples where theengagement between male spline features (9432) and female splinefeatures (9436) may be overcome by applying sufficient rotationaldisengagement force to knob (9420), the rotational force required torotate the knob (9420) in the unlocked configuration is less than therotational force required to disengage male spline features (9432) fromfemale spline features (9436).

When the operator rotates knob (9420) while knob (9420) is in theupward, unlocked position, such rotation of knob (9420) causes thearticulation of articulation section (130). Once the user hasarticulated articulation section (130) a desired amount (whether to orfrom an articulated state), the user may release the upward force onknob (9420). Springs (9440) will then resiliently urge knob (9420) backto the locked configuration of FIG. 79A, such that articulation section(130) is locked in the adjusted articulation state relative to thelongitudinal axis defined by outer sheath (32). In some examples, theoperator may need to ensure the proper alignment of male spline features(9432) with female spline features (9436) to enable the knob (9420) toreturn to the locked configuration. However, in some examples, lockingfeature (9430) may be configured to circumferentially align male splinefeatures (9432) with circumferentially adjacent female spline features(9332) to ensure a smooth transition to the locked configuration. Inother words, spline features (9432, 9436) may be configured toself-align with each other. Various suitable ways in which lockingfeature (9430) may be may be configured will be apparent to those ofordinary skill in the art in view of the teachings herein.

D. Articulation Control Assembly with Button Actuated Locking Feature

FIGS. 82-83B show another exemplary articulation control assembly (9500)that may be readily incorporated into instrument (10) in place ofarticulation control assembly (100). Except as otherwise describedbelow, articulation control assembly (9500) is configured and operablejust like articulation control assembly (100) described above.Articulation control assembly (9500) of this example comprises a housing(9510) and a knob (9520). Rotation of rotation knob (9520) relative tohousing (9510) causes articulation of an articulation section of a shaftassembly, such as articulation section (130) of shaft assembly (30).Articulation control assembly (9500) of this example further comprises alocking feature (9530) that is configured to selectively prevent therotation of knob (9520). It should be understood that, by preventingrotation of knob (9520), locking feature (9530) further preventsarticulation of the articulation section of the shaft assembly. Lockingfeature (9530) may be used in lieu of, or in addition to, other featuresdiscussed herein that selectively prevent rotation of knob (9520); andthat selectively lock articulation section (130) in a particulardeflected position relative to the longitudinal axis defined by outersheath (32).

In the present example, locking feature (9530) comprises a button (9532)that is operably coupled to a shaft (9534). Shaft (9534) is slidablyreceived in knob (9520) along the same axis about which knob (9520)rotates relative to housing (9510). Shaft (9534) has a first portion(9534 a), a second portion (9534 b), and a third portion (9534 c).Button (9532) is positioned on top of first portion (9534 a) and isconfigured to protrude above the upper surface of knob (9520) to enablean operator to readily depress button (9532) as described below. Asshown, first portion (9534 a) of shaft (9534) and button (9532) areshown to be separate components, but in other examples, button (9532)may be unitarily formed with shaft (9534). As shown, second portion(9534 b) of shaft (9534) includes a smaller cross-sectional dimension(e.g., diameter) than the first and second portions (9534 a, 9534 c).Locking feature (9530) further comprises a resilient feature (536),which in the present example is shown as a coil spring, but in otherexamples may be other types of resilient features. Resilient feature(9536) biases shaft (9534) upwardly into the position shown in FIG. 83A,whereby locking feature (9530) is in a locked configuration.

In the present example, locking feature (9530) further comprises a pairof outwardly extending engagement members (9526, 9528) including pointedends (9526 a, 9528 a). Housing (9510) includes a first cylindricalportion (9512) that has inwardly presented teeth (9516, 9518). Teeth(9516, 9518) are configured to complement engagement members (9526,9528). In particular, engagement members (9526, 9528) are configured toengage teeth (9516, 9518) in a detent relationship to therebyselectively lock the rotational position of knob (9520) relative tohousing (510). Engagement members (9526, 9528) and teeth (9516, 9518)are configured to operate substantially similar to engagement members(126, 128) with teeth (116, 118) as described above. However, in thepresent example, engagement members (9526, 9528) are retractableradially inwardly to disengage teeth (9516, 9518). A set of resilientmembers (9538, 9540) bias engagement members (9526, 9528) inwardly.Shaft (534) selectively resists this inward bias of engagement members(9526, 9528), depending on whether third portion (534 c) is positionedon the same lateral plane as engagement members (9526, 9528) or secondportion (9534 b) is positioned on the same lateral plane as engagementmembers (9526, 9528).

Shaft (9534) translates along a vertical axis to selectively positionportions (9534 b, 9534 c) on the same lateral plane as engagementmembers (9526, 9528) in response to depression and release of button(9532). In particular, when button (9532) is not being depressed, shaft(9534) is in an upper, home position as shown in FIG. 83A due to thebias of resilient feature (9536). In this state, third portion (9534 c)of shaft (9534) is positioned on the same lateral plane as engagementmembers (9526, 9528). Due to the relatively larger size of the diameterof third portion (9534 c), third portion (9534 c) holds engagementmembers (9526, 9528) in an outward position, such that pointed ends(9526 a, 9528 a) are engaged with teeth (9516, 9518). This engagementbetween pointed ends (9526 a, 9528 a) and teeth (9516, 9518) preventsknob (9520) from rotating relative to housing (9510), thereby preventingarticulation section (130) from articulating relative to the rest ofshaft assembly (30). Thus, articulation section (130) is locked at itscurrent state of articulation when locking feature (9530) is in thestate shown in FIG. 83A.

In order to unlock knob (9520), and thereby unlock articulation section(130), the operator may press button (9532) downwardly (in the directionof arrow (9538)). When button (9532) is depressed downwardly, shaft(9534) overcomes the bias of resilient feature (9536) and shaft (9534)moves downwardly. As shaft (9534) moves downwardly, radially inwardportions (9526 b, 9528 b) of engagement features (9526, 9528) ride alongthird portion (9534 c) and engagement features (9526, 9528) areeventually urged inwardly by resilient members (9538, 9540) as radiallyinward portions (9526 b, 9528 b) become coincident with second portion(9534 b) of shaft (9534), which has a smaller diameter than thirdportion (9534 c) of shaft (9534). As engagement features (9526, 9528)move inwardly as shown in FIG. 83B, pointed ends (9526 a, 9528 a) ofengagement features disengage from teeth (9516, 9518), respectively, andknob (9520) is free to rotate relative to housing (9510). The operatormay thus rotate knob (9520) while holding button (9532) in the depressedstate in order to adjust the articulation state of articulation section(130).

Once the operator has adjusted the articulation state of articulationsection (130) to a desired amount (whether to or from an articulatedstate), the operator releases button (9532). When the operator releasesbutton (9532), resilient feature (9536) urges button (9532) and shaft(9534) upwardly (in a direction opposite to arrow (9538)). As shaft(9534) travels upwardly, third portion (9534 c) of shaft (9534)eventually engages radially inward portions (9526 b, 9528 b) ofengagement features (9526, 9528), thereby driving engagement features(9526, 9528) outwardly back to the positions shown in FIG. 83A.Engagement features (9526, 9528) thus re-engage teeth (9516, 9518)respectively, thereby re-locking the rotational position of knob (9520)relative to housing (9510), and further thereby locking the adjustedarticulation state of articulation section (130). While shaft (9534) isshown as providing a stepped transition between portions (9534 b, 9534c), it should be understood that shaft (9534) may instead provide atapered transition between portions (9534 b, 9534 c). Radially innerportions (9526 b, 9528 b) of engagement members (9526, 9528) mayslidably cam along such a tapered transition portion during thetransition between the locked configuration (FIGS. 82, 83A) and unlockedconfiguration (FIG. 83B). Various other suitable ways in which lockingfeature (9530) may be may be configured will be apparent to those ofordinary skill in the art in view of the teachings herein.

E. Articulation Control Assembly with Biased and Keyed Locking Feature

FIGS. 84-89 show another exemplary articulation control assembly (9600)that may be readily incorporated into instrument (10) in place ofarticulation control assembly (100). Except as otherwise describedbelow, articulation control assembly (9600) is configured and operablejust like articulation control assembly (100) described above.Articulation control assembly (9600) of this example comprises a housing(9610) and a knob (9620). Rotation of rotation knob (9620) relative tohousing (9610) causes articulation of an articulation section of a shaftassembly, such as articulation section (130) of shaft assembly (30).Articulation control assembly (9600) of this example further comprises alocking feature (9630) that is configured to selectively prevent therotation of knob (9620). It should be understood that, by preventingrotation of knob (9620), locking feature (9630) further preventsarticulation of the articulation section of the shaft assembly. Lockingfeature (9630) may be used in lieu of, or in addition to, other featuresdiscussed herein that selectively prevent rotation of knob (9620); andthat selectively lock articulation section (130) in a particulardeflected position relative to the longitudinal axis defined by outersheath (32).

As best seen in FIG. 84, locking feature (9630) of the present exampleincludes a generally annular locking plate (9632), a coil spring (9634),and a wave spring (9636). Annular locking plate (9632) includes aradially outer edge (9638), a radially inner edge (9640), a first side(9642) and a second side (9644) (FIGS. 88A-B). Annular locking plate(9632) further includes a pair of opposing male keying features (9646 a,9646 b) extending radially outwardly from outer edge (9638), a set offirst locking teeth (9648), and a set of second locking teeth (9650).Each set of teeth (9648, 9650) has a sawtooth configuration and extendsalong only a respective portion of the angular range of first side(9642).

Different components of the locking feature (9630) are also included onthe knob (9620) and housing (9610). In particular, and as best seen inFIG. 85, knob (9620) includes a first surface (9669) and a secondsurface (9670). A handle (9672) extends upwardly from first surface(9669). Teeth (9666, 9668) extend downwardly from second surface (9670).Tooth (9666) is angularly separated from tooth (9668) by 180°. Teeth(9666, 9668) each have a sawtooth configuration such that teeth (9666,9668) are configured to engage locking teeth (9648, 9650), respectively,to selectively lock the rotational position of knob (9620) relative tohousing (9610). The complementary sawtooth configuration of tooth (9666)and teeth (9650) is such that tooth (9666) may slide along teeth (9650)in a ratcheting fashion as knob (9620) is rotated in a first angulardirection, yet the configuration of teeth (9666, 9650) will prevent knob(9620) from rotating in a second angular direction (opposite to thefirst angular direction) when teeth (9666, 9650) are engaged. Likewise,the complementary sawtooth configuration of tooth (9668) and teeth(9648) is such that tooth (9668) may slide along teeth (9648) in aratcheting fashion as knob (9620) is rotated in the second angulardirection, yet the configuration of teeth (9668, 9648) will prevent knob(9620) from rotating in the first angular direction when teeth (9668,9648) are engaged.

As also best seen in FIG. 85, knob (9620) also includes a generallycylindrical projection (9674) extending downwardly from surface (9670)and having a chamfered edge (9676). Cylindrical projection (9674) isconfigured to engage a coil spring (9634) as described below. Knob(9620) further includes a generally hemispherical protrusion (9678)extending downwardly from surface (9670). Protrusion (9678) is angularlypositioned at 90° between teeth (9666, 9668). Protrusion (9678) andhandle (9672) both lie along an imaginary vertical plane (9679) (FIG.88A) that laterally bisects knob (9670). Plane (9678) also laterallybisects handle (9672) and protrusion (9678).

In the present example, only a first cylindrical portion (9612) ofhousing (9610) is shown. It should be understood, however, that housing(9610) may further include a second cylindrical portion (not shown) thatis configured and operable substantially similar to second cylindricalportion (114) of articulation assembly housing (110). First cylindricalportion (9612) of housing (9610) is defined as a generally cylindraceousbody having a generally cylindraceous cavity. Particularly, and as bestseen in FIG. 84, cylindrical portion (9612) includes a radially outerwall (9680), a radially inner wall (9682), an upper edge (9684), and agenerally circular inner surface (9686). Radially inner wall (9682) andinner surface (9686) define a generally cylindraceous cavity (9688) thatalso includes female keying features (9690 a, 9690 b) extending radiallyoutward therefrom. An aperture (9692) extends through surface (9684) andthrough outer bottom surface (9688). Aperture (9692) provides a path forknob (9620) to couple with features like translatable members (161, 162)to thereby drive articulation bands (140, 142) in opposing longitudinaldirections in order to thereby drive articulation of articulationsection (130).

As shown best in FIGS. 84 and 86-88B, locking plate (9632), coil spring(9634), and wave spring (9636) are received in cavity (9688).Particularly, locking plate (9632), coil spring (9634), and wave spring(9636) are situated in cavity (9688) in a coaxial arrangement. Wavespring (9636) abuts surface (9686). Locking plate (9632) is positionedabove wave spring (9636) such that portions of surface (9644) of lockingplate (9632) abut wave spring (9636). Female keying portions (9690 a,9690 b) of first cylindrical portion (612) receive male keying portions(9646 a, 9646 b) of locking plate (9632). The relationship betweenkeying portions (9646 a, 9646 b, 9690 a, 9690 b) permits locking plate(9632) to translate vertically within first cylindrical portion (9612)but prevents locking plate (9632) from rotating relative to firstcylindrical portion (9612). Coil spring (9634) is sized such that theeffective outer diameter of coil spring (9634) is less than the innerdiameter defined by radially inner edge (9640) of locking plate (9632).

Knob (9620) is placed relative to the cavity (9688) such that lockingplate (9632) is generally interposed between knob (9620) and wave spring(9636). Moreover, knob (9620) is placed relative to the cavity such thatsurface (9669) of knob (9620) is generally flush with edge (9684) ofcylindrical portion (9612). A retention feature (not shown) is providedin order prevent knob (9620) from moving above edge (9684) to a pointwhere surface (9669) is above edge (9684). For instance, after the abovecomponents are assembled together, a retaining ring may be placed overedge (9684) to restrict upward vertical movement of knob (9620) relativeto first cylindrical portion (9612). Coil spring (9634) is further sizedsuch that the effective inner diameter of coil spring (9634) is lessthan the outer diameter of cylindrical projection (9674) of knob (9620).Coil spring (9634) thus receives cylindrical projection (9674) such thatcylindrical projection (9674) maintains the axial orientation of coilspring (9634) within first cylindrical member (9612).

As shown in FIGS. 86-87, knob (9620) is initially placed such thatlocking teeth (9666, 9668) are adjacent to but do not yet engage thedetent features (9648, 9650), respectively. Knob (9620) is horizontallyoriented such that surfaces (9669, 9670) are parallel to sides (9642,9644) of locking plate (9632) and inner surface (9686) of cylindricalportion (9612). At this point, knob (9620) is free to rotate relative tohousing (9610) in either a first direction or second direction about avertical axis (9602) in order to articulate the articulation section ina first or second direction. For example, rotation of knob (9620) fromthe neutral position shown in FIGS. 86-87 in a first angular directionabout axis (9602) will cause articulation of the articulation section ina first direction. As knob (9620) is rotated in the first direction,tooth (9668) ratchets along teeth (9648). Tooth (9666) simply slidesalong (or moves freely above) first side (9642) of locking plate (9632).When the operator thereafter releases knob (9620), engagement betweenteeth (9668, 9648) will lock the articulation section in the selectedstate of articulation. In other words, engagement between teeth (9668,9648) will lock articulation control assembly (9600), thereby lockingthe articulation section in an articulated state.

Similarly, rotation of knob (9620) from the neutral position shown inFIGS. 86-87 in a second angular direction about axis (9602) will causearticulation of the articulation section in a second direction. As knob(9620) is rotated in the second direction, tooth (9666) ratchets alongteeth (9650). Tooth (9668) simply slides along (or moves freely above)first side (9642) of locking plate (9632). When the operator thereafterreleases knob (9620), engagement between teeth (9666, 9650) will lockthe articulation section in the selected state of articulation. In otherwords, engagement between teeth (9666, 9650) will lock articulationcontrol assembly (9600), thereby locking the articulation section in anarticulated state.

When the operator wishes to unlock articulation control assembly (9600)and the articulation section (e.g., to return the articulation sectionto a straight configuration), the operator may tilt the proximal end ofknob (9620) downwardly about a horizontal axis (9696) as shown in FIGS.88A-89. In particular, FIG. 88A shows articulation control assembly(9600) before knob (9620) is tilted, while articulation control assembly(9600) is still in a locked state. As the proximal end of knob (9620) istilted downwardly about horizontal axis (9696), protrusion (9678) bearsdownwardly on first side (9642) of locking plate (9632), thereby drivinglocking plate (9632) downwardly as shown in FIGS. 88B and 89. As lockingplate (9632) is driven downwardly, whichever tooth (9666, 9668) that waspreviously engaged with the corresponding teeth (9650, 9648) willdisengage teeth (9650, 9648), thereby transitioning articulation controlassembly (9600) to an unlocked state. While holding knob (9620) in thetilted orientation, the operator may rotate knob (9620) in eitherdirection about axis (9602) to re-adjust the state of articulation ofthe articulation section. Once the articulation section has reached thedesired re-adjusted state, the operator may release knob (9620). At thispoint, the resilience of coil spring (9634) will drive knob (9620) backto the horizontal orientation shown in FIGS. 86-88A.

F. Articulation Control Assembly with Resiliently Biased Control Wheeland Locking Feature

FIGS. 90A-90B show exemplary alternative articulation control assembly(9700) that may be readily incorporated into instrument (10) in place ofarticulation control assembly (100). Articulation control assembly(9700) of the present example is configured to articulate articulationsection (130) in a substantially similar manner to articulation controlassembly (100), except for the differences described below. Articulationcontrol assembly (9700) is secured to a proximal portion of outer sheath(32) of shaft assembly (30). Articulation control assembly (9700) islocated within a body (9702) of a handle assembly. Except as otherwisedescribed herein, body (9702) and the rest of the handle assembly may beconfigured similar to body (22) and the rest of handle assembly (20) ofinstrument (10).

Articulation control assembly (9700) of the present example includes arotatable input wheel (9704) that is configured to translate and rotaterelative to body (9702). Input wheel (9704) includes an integral gear(9706). Wheel (9704) and gear (9706) are rotatable about an axis (9708).Wheel (9704) and gear (9706) are further coupled with a rigid arm(9734). Arm (9734) is further coupled with a pawl (9732) and a resilientmember (9736). Resilient member (9736) is mounted to body (9702) and isconfigured to bias wheel (9704) and gear (9706) to the position shown inFIG. 90A.

Articulation control assembly (9700) of the present example furtherincludes a transmission gear (9710), a first bevel gear (9712), and asecond bevel gear (9718). Transmission gear (9710) and first bevel gear(9712) are unitarily coupled together via a shaft (9714), such thatgears (9710, 9712) rotate together unitarily. Bevel gears (9712, 9718)are in a meshing relationship with each other, such that rotation offirst bevel gear (9712) will provide rotation of second bevel gear(9718). Second bevel gear (9718) is coupled with an opposing threadtransmission assembly (9720), which is further coupled with translatingmembers (9761, 9762). Transmission assembly (9720) is configured toconvert a rotary output from second bevel gear (9718) into opposinglongitudinal motion of translating members (9761, 9762). Translatingmembers (9761, 9762) are coupled with respective articulation bandssimilar to articulation bands (140, 142), such that opposinglongitudinal motion of translating members (9761, 9762) providesarticulation of an articulation section in a shaft assembly.

In some versions, transmission assembly (9720) comprises a first nut andlead screw assembly associated with first translating member (9761); anda second nut and lead screw assembly associated with second translatingmember (9761). The second nut and lead screw assembly may have a threadorientation that is opposite from the thread orientation of the firstnut and lead screw assembly, such that the lead screw assemblies mayprovide opposing longitudinal motion from a single rotary input that isshared by both of the lead screw assemblies. By way of example only,transmission assembly (9720) may be configured in accordance with atleast some of the teachings of U.S. Pub. No. 2013/0023868, issued asU.S. Pat. No. 9,545,253 on Jan. 17, 2017, entitled “Surgical Instrumentwith Contained Dual Helix Actuator Assembly,” published Jan. 24, 2013,the disclosure of which is incorporated by reference herein. Othersuitable configurations for transmission assembly (9720) will beapparent to those of ordinary skill in the art in view of the teachingsherein.

Articulation control assembly (9700) is configured to transition betweena locked state (FIG. 90A) and a driving state (FIG. 90B). In the lockedstate, gear (9706) is disengaged from gear (9710) and pawl (9732) isengaged with gear (9710). Pawl (9732) prevents gear (9710) fromrotating. With gear (9710) locked by pawl (9732), gears (9712, 9718) andtransmission assembly (9720) are also locked. With transmission assembly(9720) locked, translating members (9761, 9762) are also locked, therebylocking the articulation section in its current state of articulation.If the operator attempts to rotate wheel (9704) about axis (9708) whenarticulation control assembly (9700) is in the locked state, wheel(9704) will simply rotate freely without having any other effect.Alternatively, body (9702) may include an integral pawl feature thatengages wheel (9704) or gear (9706) when articulation control assembly(9700) is in the locked state. Such a pawl may prevent wheel (9704) fromrotating when articulation control assembly (9700) is in the lockedstate, thereby providing tactile feedback to the operator to indicatethat articulation control assembly (9700) is in the locked state.

When the operator wishes to change the articulation state of thearticulation section (e.g., articulation section (130) described above),the operator may transition articulation control assembly (9700) to thedriving state by pushing/pulling wheel (9704) proximally from theposition shown in FIG. 90A to the position shown in FIG. 90B. This willeventually bring gear (9706) into engagement with gear (9710). Inaddition, the proximal movement of wheel (9704) will be communicated topawl (9732) via arm (9734), such that pawl (9732) will disengage gear(9710) as shown in FIG. 90B. The proximal movement of arm (9734) alsocompresses resilient member (9736). With pawl (9732) disengaged fromgear (9710), gear (9710) is free to rotate. With gear (9706) engagedwith gear (9710), rotation of wheel (9704) will cause rotation of gear(9710). It should therefore be understood that rotation of wheel (9704)will actuate transmission assembly (9720), thereby providing opposinglongitudinal motion of translating members (9761, 9762), whenarticulation control assembly (9700) is in the driving as shown in FIG.90B. In other words, rotation of wheel (9704) about axis (9708) willdrive articulation of the articulation section of the shaft assemblywhen articulation control assembly (9700) is in the driving as shown inFIG. 90B.

Once the operator has achieved the desired state of articulation in thearticulation section of the shaft assembly, the operator may simplyrelease wheel (9704). When the operator releases wheel (9704), resilientmember (9736) will drive wheel (9704), gear (9706), and pawl (9732) backto the positions shown in FIG. 90A, thereby transitioning articulationcontrol assembly (9700) back to the locked state. This will lock thearticulation assembly in the adjusted state of articulation. Variousother suitable ways in which articulation control assembly (9700) may beconfigured and operated will be apparent to a person skilled in the artin view of the teachings herein.

G. Articulation Control Assembly with Self-Locking Linear Cam Features

FIGS. 91A-92B show another exemplary alternative articulation controlassembly (9800) that may be readily incorporated into instrument (10) inplace of articulation control assembly (100). Articulation controlassembly (9800) is configured to articulate articulation section (130)in a substantially similar manner to articulation control assembly(100), except for the differences described below. Articulation controlassembly (9800) is secured to a proximal portion of outer sheath (32) ofshaft assembly (30).

In the present example, articulation control assembly (9800) comprises afirst collar (9802), a second collar (9804), and a rotatable knob(9806). Rotation of knob (9806) causes the articulation of articulationsection (130), as discussed in more detail below. Articulation controlassembly (9900) further includes an actuator (9807) with opposing firstand second cam plates (9808 a, 9808 b). First collar (9802) includes afirst pin (9810) extending transversely therefrom. First pin (9810) isreceived in a first cam channel (9812) of cam plate (9808 a). Secondcollar (9804) includes a second pin (9814) extending transverselytherefrom. Second pin (9814) is received in a second cam channel (9816)of cam plate (9808). As best seen in FIGS. 92A-92B, cam channels (9812,816) each extend obliquely relative to a vertical axis (9832). Inaddition, first cam channel (9812) tilts distally while second camchannel (9816) tilts proximally.

Shaft assembly (30) comprises a pair of articulation bands (9840, 9842)that are coupled to first and second collars (9802, 9804) via pins(9820, 9822), respectively. Articulation bands (9840, 9842) areconfigured to operate substantially similar to articulation bands (140,142), such that opposing longitudinal translation of articulation bands(9840, 9842) causes articulation of articulation section (130).Articulation bands (9840, 9842) extend slidably and longitudinallythrough the proximal portion of outer sheath (32). Pin (9820) isreceived within annular groove (9824) of first collar (9802), and pin(9822) is received within annular groove (9826) of second collar (9804).Thus, as shaft assembly (30) rotates relative to articulation controlassembly (9800), pin (9820) rotates within annular groove (9824), andpin (9822) rotates within annular groove (9826). Pins (9820, 9822) aremechanically coupled with respective articulation bands (9840, 9842),respectively, such that longitudinal translation of pin (9820) causeslongitudinal translation of articulation band (9840), and such thatlongitudinal translation of pin (9822) causes longitudinal translationof articulation band (9842).

Actuator (9807) of the present example includes a threaded bore (9828)that is configured to threadably couple with a threaded rod (9830) thatis coupled to knob (9806). Knob (9806) and threaded rod (9830) are fixedtogether along an axis (9832) such that rotation of knob (9806) causesactuator to move longitudinally along axis (9832) due to the threadedcoupling between threaded rod (9830) and actuator (9807). For example,rotating knob (9806) in a first direction causes actuator (9807) to movein a direction away from knob (9806) along axis (9832), and along aplane that is perpendicular to the longitudinal axis of outer sheath(32). Rotating knob (9806) in a second direction causes actuator (9807)to move toward knob (9807) along axis (9832), and along a plane that isperpendicular to the longitudinal axis of outer sheath (32).

As shown in the transition from FIG. 92A to FIG. 92B, knob (9806) hasbeen rotated in a direction that has caused actuator (9807) to move awayfrom knob (9806). Due to the configuration of cam channels (9812, 9816),the movement of actuator (9807) away from knob (9806) causes pins (9810,9814) to follow cam channels (9812, 9816). Thus, pin (9810) is urged ina proximal direction by cam channel (9812), thereby causing proximaltranslation of collar (9802). Similarly, pin (9814) is urged in a distaldirection by cam channel (9816), thereby causing distal translation ofcollar (9804). Due to the coupling engagement between collar (9902) andarticulation band (9940), the proximal translation of collar (9802)causes the proximal translation of articulation band (9840). Similarly,due to the coupling engagement between collar (9804) and articulationband (9842), the distal translation of collar (9804) causes the distaltranslation of articulation band (9842). Thus, articulation bands (9840,9842) translate simultaneously in opposing longitudinal directions inresponse to rotation of knob (9806). Rotation of knob (9806) willthereby change the articulation state of articulation section (130).

It should be understood that pins (9810, 9814) and cam channels (9812,9816) may be positioned and arranged such that rotation of knob (9806)in a first angular direction will cause articulation section (130) todeflect in a first lateral direction away from the longitudinal axis ofouter sheath (32); while rotation of knob (9806) in a second angulardirection will cause articulation section (130) to deflect in a secondlateral direction away from the longitudinal axis of outer sheath (32).It should also be understood that, due to the configuration andarrangement of pins (9810, 9814) and cam channels (9812, 9816),articulation control assembly (9800) may provide self-locking ofarticulation section (9130). In other words, friction between pins(9810, 9814) and cam channels (9812, 9816) may prevent articulationsection (130) from inadvertently deflecting away from a selected stateof articulation unless and until the operator rotates knob (9806).

H. Articulation Control Assembly with Self-Locking Rotary Cam Features

FIGS. 93A-94B show another exemplary alternative articulation controlassembly (9900) that may be readily incorporated into instrument (10) inplace of articulation control assembly (100). Articulation controlassembly (9900) is configured to articulate articulation section (130)in a substantially similar manner to articulation control assembly(100), except for the differences described below. Articulation controlassembly (9900) is secured to a proximal portion of outer sheath (32) ofshaft assembly (30).

Articulation control assembly (9900) comprises a first collar (9902), asecond collar (9904), a rotatable knob (9906), and a cam plate (9908).Cam plate (9908) is coupled to rotatable knob (9906) such that rotationof rotatable knob (9906) causes rotation of cam plate (9908). Firstcollar (9902) includes a first pin (9910) extending transverselytherefrom. First pin (9910) is received in a first cam channel (9912) ofcam plate (9908). Second collar (9904) includes a second pin (9914)extending transversely therefrom. Second pin (9914) is received in asecond cam channel (9916) of cam plate (9908).

Shaft assembly (30) comprises a pair of articulation bands (9940, 942)that are coupled to first and second collars (9902, 904) via pins (9920,9922), respectfully. Articulation bands (9940, 9942) are configured tooperate substantially similar to articulation bands (140, 142), suchthat opposing longitudinal translation of articulation bands (9940,9942) causes articulation of articulation section (130). Articulationbands (9940, 9942) extend slidably and longitudinally through theproximal portion of outer sheath (32). Pin (9920) is received withinannular groove (9924) of first collar (9902), and pin (9922) is receivedwithin annular groove (9926) of second collar (9904). Thus, as shaftassembly (30) rotates relative to articulation control assembly (9900),pin (9920) rotates within annular groove (9924) and pin (9922) rotateswithin annular groove (9926). Pins (9920, 9922) are mechanically coupledwith respective articulation bands (9940, 9942) such that longitudinaltranslation of pin (9920) causes longitudinal translation ofarticulation band (9940), and such that longitudinal translation of pin(9922) causes longitudinal translation of articulation band (9942).

As shown in the transition from FIG. 94A to FIG. 94B, knob (9906) hasbeen rotated in a direction that has caused cam plate (9908) to movecounterclockwise. Due to the configuration of cam channels (9912, 9916),the counterclockwise rotation of cam plate (9908) causes pins (9910,9914) to follow cam channels (9912, 9916) such that pin (9910) is urgeddistally while pin (9914) is urged proximally. The proximal movement ofpin (9910) provides proximal movement of collar (9902), which in turncauses proximal movement of articulation band (9940). The distalmovement of pin (9914) provides distal movement of collar (9904), whichin turn causes distal movement of articulation band (9942). Thus,articulation bands (9940, 9942) translate simultaneously in opposinglongitudinal directions in response to rotation of knob (9906). Rotationof knob (9906) will thereby change the articulation state ofarticulation section (130).

It should be understood that pins (9910, 9914) and cam channels (9912,9916) may be positioned and arranged such that rotation of knob (9906)in a first angular direction will cause articulation section (130) todeflect in a first lateral direction away from the longitudinal axis ofouter sheath (32); while rotation of knob (9906) in a second angulardirection will cause articulation section (130) to deflect in a secondlateral direction away from the longitudinal axis of outer sheath (32).It should also be understood that, due to the configuration andarrangement of pins (9910, 9914) and cam channels (9912, 9916),articulation control assembly (9900) may provide self-locking ofarticulation section (130). In other words, friction between pins (9910,9914) and cam channels (9912, 9916) may prevent articulation section(130) from inadvertently deflecting away from a selected state ofarticulation unless and until the operator rotates knob (9906).

XI. INSTRUMENT WITH ROTATABLE SHAFT HAVING PLURALITY OF LOCKINGPOSITIONS

As noted above, ultrasonic surgical instrument (10) has a shaft assembly(30) that is rotatable via knob (31). It should be understood that otherinstruments may also have rotatable shaft assemblies. For instance, FIG.95 shows an exemplary electrosurgical instrument (10110). By way ofexample only, electrosurgical instrument (10110) may be constructed andoperable in accordance with at least some of the teachings of U.S. Pat.No. 6,500,176; U.S. Pat. No. 7,112,201; U.S. Pat. No. 7,125,409; U.S.Pat. No. 7,169,146; U.S. Pat. No. 7,186,253; U.S. Pat. No. 7,189,233;U.S. Pat. No. 7,220,951; U.S. Pat. No. 7,309,849; U.S. Pat. No.7,311,709; U.S. Pat. No. 7,354,440; U.S. Pat. No. 7,381,209; U.S. Pat.No. 8,888,809; U.S. Pub. No. 2011/0087218, issued as U.S. Pat. No.8,939,974 on Jan. 27, 2015; U.S. Pub. No. 2012/0116379, issued as U.S.Pat. No. 9,161,803 on Oct. 20, 2015; U.S. Pub. No. 2012/0078243; U.S.Pub. No. 2012/0078247, issued as U.S. Pat. No. 9,402,682 on Aug. 2,2016; U.S. Pub. No. 2013/0030428, issued as U.S. Pat. No. 9,089,327 onJul. 28, 2015; and/or U.S. Pub. No. 2013/0023868, issued as U.S. Pat.No. 9,545,253 on Jan. 17, 2017. As described therein and as will bedescribed in greater detail below, electrosurgical instrument (10110) isoperable to cut tissue and seal or weld tissue (e.g., a blood vessel,etc.) substantially simultaneously. In other words, electrosurgicalinstrument (10110) operates similar to an endocutter type of stapler,except that electrosurgical instrument (10110) provides tissue weldingthrough application of bipolar RF energy instead of providing lines ofstaples to join tissue.

It should also be understood that electrosurgical instrument (10110) mayhave various structural and functional similarities with the ENSEAL®.Tissue Sealing Device by Ethicon Endo-Surgery, Inc., of Cincinnati,Ohio. Furthermore, electrosurgical instrument (10110) may have variousstructural and functional similarities with the devices taught in any ofthe other references that are cited and incorporated by referenceherein. To the extent that there is some degree of overlap between theteachings of the references cited herein, the ENSEAL®. Tissue SealingDevice by Ethicon Endo-Surgery, Inc., of Cincinnati, Ohio, and thefollowing teachings relating to electrosurgical instrument (10110),there is no intent for any of the description herein to be presumed asadmitted prior art. Several teachings below will in fact go beyond thescope of the teachings of the references cited herein and the ENSEAL®.Tissue Sealing Device by Ethicon Endo-Surgery, Inc., of Cincinnati,Ohio.

Electrosurgical instrument (10110) of the present example includes ahandle assembly (10120), a shaft assembly (10130) extending distallyfrom handle assembly (10120), and an end effector (10140) disposed at adistal end of shaft assembly (10130). Handle assembly (10120) of thepresent example includes a body (10122), a pistol grip (10124), anactivation button (10126), and a pivoting trigger (10128). Trigger(10128) is pivotable toward and away from pistol grip (10124) toselectively actuate end effector (10140) as will be described in greaterdetail below. Activation button (10126) is operable to selectivelyactivate RF circuitry that is in communication with end effector(10140), as will also be described in greater detail below. In someversions, activation button (10126) also serves as a mechanical lockoutagainst trigger (10128), such that trigger (10128) cannot be fullyactuated unless button (10126) is being pressed simultaneously. Examplesof how such a lockout may be provided are disclosed in one or more ofthe references cited herein. It should be understood that pistol grip(10124), trigger (10128), and button (10126) may be modified,substituted, supplemented, etc. in any suitable way, and that thedescriptions of such components herein are merely illustrative.

Shaft assembly (10130) of the present example includes an outer sheath(10132). In some merely illustrative variations, shaft assembly (10130)also includes an articulation section (not shown) that is operable toselectively position end effector (10140) at various angles relative tothe longitudinal axis defined by sheath (10132). Handle assembly (10120)may include one or more control features that are operable to drivearticulation of the articulation section. By way of example only, anarticulation section and associated control features may be configuredin accordance with at least some of the teachings of the variousreferences cited herein. Of course, as in the present example, shaftassembly (10130) may simply lack an articulation section if desired.

End effector (10140) of the present example comprises a first jaw(10142) and a second jaw (10144). In the present example, first jaw(10142) is substantially fixed relative to shaft assembly (10130); whilesecond jaw (10144) pivots relative to shaft assembly (10130), toward andaway from second jaw (10142). In some versions, actuators such as rodsor cables, etc., may extend through sheath (10132) and be joined withsecond jaw (10144) at a pivotal coupling (not shown), such thatlongitudinal movement of the actuator rods/cables/etc. through shaftassembly (10130) provides pivoting of second jaw (10144) relative toshaft assembly (10130) and relative to first jaw (10142) in response topivoting of trigger (10128) relative to pistol grip (10124). Of course,jaws (10142, 10144) may instead have any other suitable kind of movementand may be actuated in any other suitable fashion.

In the present example, each jaw (10142, 10144) includes at least oneelectrode surface that is in communication with an electrical source(10116). Electrical source (10116) is operable to deliver RF energy tothose electrodes at respective polarities such that RF current flowsbetween the electrode surfaces of jaws (10142, 10144) and therebythrough tissue captured between jaws (10142, 10144). The RF energy maybe delivered in response to the operator pressing button (10126) whiletissue is clamped between jaws (10142, 10144). While electrical source(10116) is shown as being external to electrosurgical instrument(10110), electrical source (10116) may be integral with electrosurgicalinstrument (10110) (e.g., in handle assembly (10120), etc.), asdescribed in one or more references cited herein or otherwise. Acontroller (not shown) regulates delivery of power from electricalsource (10116) to the electrode surfaces. The controller may also beexternal to electrosurgical instrument (10110) or may be integral withelectrosurgical instrument (10110) (e.g., in handle assembly (10120),etc.), as described in one or more references cited herein or otherwise.It should also be understood that the electrode surfaces may be providedin a variety of alternative locations, configurations, andrelationships.

In some versions, end effector (10140) includes one or more sensors (notshown) that are configured to sense a variety of parameters at endeffector (10140), including but not limited to temperature of adjacenttissue, electrical resistance or impedance of adjacent tissue, voltageacross adjacent tissue, forces exerted on jaws (10142, 10144) byadjacent tissue, etc. By way of example only, end effector (10140) mayinclude one or more positive temperature coefficient (PTC) thermistorbodies (e.g., PTC polymer, etc.), located adjacent to the electrodesand/or elsewhere. Data from sensors may be communicated to thecontroller. The controller may process such data in a variety of ways.By way of example only, the controller may modulate or otherwise changethe RF energy being delivered to the electrode surfaces, based at leastin part on data acquired from one or more sensors at end effector(10140). In addition or in the alternative, the controller may alert theoperator to one or more conditions via an audio and/or visual feedbackdevice (e.g., speaker, lights, display screen, etc.), based at least inpart on data acquired from one or more sensors at end effector (10140).It should also be understood that some kinds of sensors need notnecessarily be in communication with the controller, and may simplyprovide a purely localized effect at end effector (10140). For instance,PTC thermistor bodies at end effector (10140) may automatically reducethe energy delivery at the electrode surfaces as the temperature of thetissue and/or end effector (10140) increases, thereby reducing thelikelihood of overheating, in accordance with the teachings of one ormore references cited herein. Various ways in which sensors that may beincorporated into electrosurgical instrument (10110) will be apparent tothose of ordinary skill in the art in view of the teachings herein.

By way of example only, and as is described in various references citedherein, jaws (10142, 10144) may be actuated and thus closed bylongitudinal translation of a firing beam (not shown). The firing beammay be longitudinally movable along part of the length of end effector(10140). The firing beam may be coaxially positioned within shaftassembly (10130), extend along the length of shaft assembly (10130), andtranslate longitudinally within shaft assembly (10130). The firing beammay include a sharp distal blade that severs tissue that is capturedbetween jaws (10142, 10144). The firing beam may also include a set offlanges that engage jaws (10142, 10144) and thereby drive jaw (10144)toward jaw (10142) as the firing beam is advanced distally through endeffector (10140). The flanges may also drive jaw (10144) away from jaw(10142) as the firing beam is retracted to a proximal position. Theflanges may provide the firing beam with an “I-beam” type of crosssection at the distal end of the firing beam. Alternatively, pins orother structural features may be used instead of flanges. In someversions, the firing beam is also electrically grounded, providing areturn path for RF energy that is delivered to the captured tissue viathe electrodes in jaws (10142, 10144).

As shown in FIG. 95, a knob (10134) is secured to a proximal portion ofouter sheath (10132). Knob (10134) is rotatable relative to body(10122), such that shaft assembly (10130) is rotatable about thelongitudinal axis defined by outer sheath (10132), relative to handleassembly (10120). Such rotation may provide rotation of end effector(10140) and shaft assembly (10130) unitarily. It may be desirable toactuate knob (10134) to rotate end effector (10140) and shaft assembly(10130) in order to suitably orient the clamping plane of jaws (10142,10144) relative to targeted tissue.

In some instances, it may be desirable to selectively prevent and permitrotatability of shaft assembly (10130) relative to handle assembly(10120) by locking and unlocking features of shaft assembly (10130)relative to handle assembly (10120). For instance, it may be desirableto prevent shaft assembly (10130) from being inadvertently rotated aboutits longitudinal axis due to incidental contact between the operator'shand and knob (10134), due to incidental contact between end effector(10140) and an anatomical structure in the patient, and/or due to otherconditions. It may be particularly desirable to prevent shaft assembly(10130) from being inadvertently rotated about its longitudinal axisonce end effector (10140) has been positioned adjacent to targetedtissue, right before or during actuation of clamp arm or second jaw(10144) to compress the tissue against blade or first jaw (10142),respectively. In the context of instrument (10) where shaft assembly(30) includes an articulation section (36), it may be desirable toprevent rotation of shaft assembly (30) about the longitudinal axisafter articulation section (36) has been bent or otherwise deflected toan articulated state. In any of the foregoing scenarios, inadvertentrotation of shaft assembly (30, 10130) may frustrate the operator andrequire the operator to reposition end effector (40, 10140) relative tothe targeted tissue.

Thus, it may be desirable to provide rotatability of shaft assembly(10130) before and during positioning of end effector (10140); yetprevent rotatability of shaft assembly (10130) once end effector (10140)has been suitably positioned relative to targeted tissue. Variousexamples of how rotatability of shaft assembly (10130) may beselectively locked and unlocked will be described in greater detailbelow. Other examples will be apparent to those of ordinary skill in theart in view of the teachings herein.

While several of the teachings below are described as variations toultrasonic surgical instrument (10) and/or electrosurgical instrument(10110), it should be understood that various teachings below may alsobe incorporated into various other types of devices. By way of exampleonly, in addition to being readily incorporated into ultrasonic surgicalinstrument (10) and electrosurgical instrument (10110), variousteachings below may be readily incorporated into the devices taught inany of the references cited herein, other types of electrosurgicaldevices, surgical staplers, surgical clip appliers, and tissue graspers,among various other devices. Other suitable devices into which thefollowing teachings may be incorporated will be apparent to those ofordinary skill in the art in view of the teachings herein.

A. Exemplary Knob-Driven Clamping Lock for Shaft Assembly

One exemplary feature that may be used to prevent inadvertent rotationof end effector (10140) about the longitudinal axis defined by sheath(10132) is a spring clamp (10200), as shown in FIGS. 96-99E. As bestseen in FIG. 96, a shaft assembly (10260) extends distally from a handleassembly (10210), which comprises a pair of housing halves (10212,10214). Handle assembly (10210) may be configured like handle assembly(20), like handle assembly (10120), or have any other suitableconfiguration. Each housing half (10212, 10214) in this examplecomprises a respective, distally extending boss (10216, 10218). Bosses(10216, 10218) cooperate to form an annular shape. This annular shapeformed by bosses (10216, 10218) is concentric with shaft assembly(10260). Shaft assembly (10260) comprises an outer sheath (10262) and arotation knob (10270), which is operable to rotate outer sheath (10262)and other components of shaft assembly (10260) relative to handleassembly (10210) as described in greater detail below. Shaft assembly(10260) may be configured like shaft assembly (30), like shaft assembly(10130), or have any other suitable configuration. It should beunderstood that the distal end of shaft assembly (10260) may include anend effector like end effector (40), an end effector like end effector(10140), and/or any other suitable kind of end effector.

Spring clamp (10200) comprises a resilient annular surface (10220),notches (10225, 10240), a proximal edge (10245), an offset distal edge(10235), and strips (10230, 10231, 10232) that terminate into radiallyextending tabs (10205, 10210, 10215). Resilient annular surface (10220)terminates on one end with single strip (10232) and terminates on theother end with two strips (10230, 10231). Two strips (10230, 10231) forma U-shaped pathway that is configured to receive single strip (10232).The resilient properties of spring clamp (10200) ensure that singlestrip (10232) and two strips (10230, 10231) angularly overlap towardeach other in such a way as to conform to bosses (10216, 10218). Inother words, spring clamp (10230) is resiliently biased in a firstposition where interior of resilient annular surface (10220) engagesbosses (10216, 10218) in such a way that spring clamp (10230) and bosses(10216, 10218) are fixed relative to one another in the first position.Proximal edge (10245) is positioned against handle housing halves(10212, 10214) while offset distal edge (10235) aligns flush with thedistal ends of bosses (10216, 10218). Notches (10225, 10240) extendlongitudinally past bosses (10216, 10218) as best seen in FIG. 96. Whilenotches (10225, 10240) are used in the current examples, other featurescan be implemented onto spring clamp (10200) such as slots or bent tabssimilar to radially extending tabs (10205, 10210, 10215).

As best seen in FIG. 97, notches (10225) are in contact with a shaftretainer (10300). Shaft retainer (10300) is unitarily fixed to distalouter sheath (10262), such that rotation of shaft retainer (10300)rotates outer sheath (10262) and the rest of shaft assembly (10260)relative to handle assembly (10210). Shaft retainer (10300) comprises aproximal annular flange (10210), a body (10315), and a distal annularflange (10305) with a cutout (10340). Body (10315) is dimensioned to fitwithin bosses (10216, 10218). The outer diameter of body (10315) is lessthan the inner diameter defined by bosses (10216, 10218), such thatshaft retainer (10300) may freely rotate within bosses (10216, 10218)when spring clamp (10200) is in an unlocked state (i.e., in the secondposition). Outer sheath (10262) is fixedly secured within the interiorof body (10315). Body (10315) also connects proximal annular flange(10210) with distal annular flange (10305). Proximal annular flange(10210) further comprises contact surface (10320) that is configured toengage the proximal ends of bosses (10216, 10218). Spring clamp (10200)engages shaft retainer (10300) due to contact between the outer edges ofnotches (10225) and the inner edges of cutout (10340).

As best seen in FIG. 98, rotation knob (10270) encompasses bosses(10216, 10218), spring clamp (10200) and at least a portion of shaftretainer (10300). Rotation knob (10270) comprises a plurality ofrotation grips (10272), a rotation channel (10274), and a key slot(10276) extending from a portion of rotation channel (10274). Rotationchannel (10274) forms a recess that encompasses bosses (10216, 10218), aportion of spring clamp (10200), and a portion of shaft retainer(10300). Key slot (10276) provides additional space for radiallyextending tabs (10205, 10210, 10215). However, rotation knob (10270) isnot directly in contact with shaft retainer (10300) or outer sheath(10262). Therefore, rotation of knob (10270) does not directly correlateto rotation of shaft assembly (10260).

As described below, knob (10270) is configured to interact with springclamp (10200) in order to transition spring clamp (10200) from firstposition to a second position. When spring clamp (10200) is in the firstposition, spring clamp (10200) resiliently bears radially inwardlyagainst bosses (10216, 10218), such that spring clamp (10200) iseffectively locked to handle assembly (10210) due to a frictionalbraking effect. This effect is transferred to shaft assembly (10260) viashaft retainer (10300) due to engagement between the outer edges ofnotches (10225) and the inner edges of cutout (10340). In other words,when spring clamp (10200) is in the first position, shaft retainer(10300), spring clamp (10200), and bosses (10216, 10218) all cooperateto effectively lock the rotational position of shaft assembly (10260)relative to handle assembly (10210). When spring clamp (10200)transitions to the second position, the grip of spring clamp (10200)against bosses (10216, 10217) is relieved, reducing or eliminatingfrictional braking of spring clamp (10200) against bosses (10216,10217), thereby allowing shaft assembly (10260) to rotate relative tohandle assembly (10210).

The fact that spring clamp (10200) transitions from the first positionto the second position in response to actuation of rotation knob (10270)may also provide other results. For example, if outer sheath (10262)encounters incidental rotational forces due to the end effector bearingagainst anatomical structures of the patient during operation of theinstrument in a surgical procedure, these incidental rotation forceswill not cause spring clamp (10200) to release. Instead, theseincidental rotation forces will further tighten spring clamp (10200),such that spring clamp (10200) will provide further resistance torotation of shaft assembly (10260). Thus, actual rotation of knob(10270) will be required in order to release spring clamp (10200) topermit rotation of shaft assembly (10260).

FIG. 99A shows rotation knob (10270) and spring clamp (10200) in anon-engaged relationship, such that tabs (10205, 10210, 10215) arepositioned within key slot (10276) without engaging any interiorsurfaces of knob (10270) that define key slot (10276). At this point,spring clamp (10200) is still in a first position, clamping againstbosses (10216, 10218), thereby effectively locking the rotationalposition of shaft assembly (10260) relative to handle assembly (10210).FIG. 99B shows rotation knob (10270) rotated to an angular positionwhere an interior surface of knob (10270) defining key slot (10276) isin contact with radially extending tab (10215), but where spring clamp(10200) is still in the first position. This is the maximum amount ofrotation that knob (10270) is allowed without rotating shaft assembly(10260) via shaft retainer (10300). It should therefore be understoodthat there is some “play” between knob (10270) and shaft assembly(10260), such that there is lost motion between knob (10270) and shaftassembly (10260) as knob (10270) is rotated through a first range ofangular motion from the position shown in FIG. 99A to the position shownin FIG. 99B.

FIG. 99C shows rotation knob (10270) rotated further to an angularposition where the surface of key slot (10276) that initially contactedtab (10215) at the stage shown in FIG. 99B is now bearing against tab(10215) with enough force to cause spring clamp (10200) to deform to thesecond position. As noted above, when spring clamp (10200) is in thesecond position, spring clamp (10200) the braking force of spring clamp(10200) against bosses (10216, 10218) is substantially relieved suchthat spring clamp (10200) may be rotated relative to bosses (10216,10218). Therefore, as seen in the transition from the stage shown inFIG. 99C to the stage shown in FIG. 99D, further rotation of knob(10270) provides rotation of spring clamp (10200) about bosses (10216,10218). Additionally, since notches (10225, 10240) are in direct contactwith cutouts (10340) of distal annular flange (10305), rotation ofspring clamp (10200) also rotates shaft retainer (10300), therebyrotating shaft assembly (10260) (and the end effector (not shown) at thedistal end of shaft assembly (10260)). In other words, as key slot(10276) of rotation knob (10270) engages radially extending tab (10215)of spring clamp (10200), spring clamp (10200) becomes free to rotaterelative to handle housing halves (10212, 10214) while simultaneouslyrotating shaft assembly (10260) due to contact between spring clamp(10200) and shaft retainer (10300).

As seen in the transition from the stage shown in FIG. 99C to the stageshown in FIG. 99D, once the operator has rotated knob (10270) to orientshaft assembly (10260) at the desired angular position, the operatorthen release knob (10270). When the operator releases knob (10270), theresilient properties of spring clamp (10200) pushes spring clamp fromthe second position back to the first position. Spring clamp (10200) isthen again rotationally fixed relative to bosses (10216, 218), therebyeffectively locking the rotational position of shaft assembly (10260)relative to handle assembly (10210). While FIG. 99A depict rotation ofknob (10270) and shaft assembly (10260) in just one angular direction,it should be understood that the above described components will operatein the same fashion when knob (10270) and shaft assembly (10260) arerotated in the opposite angular direction.

FIGS. 96-99E show spring clamp (10200) in a flat spring form. However,spring clamp (10200) may take a variety of alternative forms such as around wire form. Additionally, spring clamp (10200) can have otherfeatures for engaging key slot (10276) instead of radially extendingtabs (10205, 10210, 10215). Additionally, it is not necessary for springclamp (10200) to comprise two strips (10230, 10231) in order to form aU-shaped pathway and angularly overlap toward single strip (10232). Forinstance, two strips (10230, 10231) could be a single strip that doesnot overlap single strip (10232) of the present example. In some suchversions, a boss could be inserted on knob (10270) instead of key slot(10276) to engage either strip. Various suitable alternativeconfigurations and relationships for spring clamp (10200) and knob(10270) will be apparent to those of ordinary skill in the art in viewof the teachings herein.

B. Exemplary Trigger-Driven Clutching Lock for Shaft Assembly

In some circumstances, it may be desirable to tie the locking of theangular position of shaft assembly (10130) to some other operation ofinstrument (10100). For instance, it may be desirable to lock rotationof shaft assembly (10130) relative to handle assembly (10120) whentrigger (10128) is being actuated; yet permit shaft assembly (10130) tobe rotated relative to handle assembly (10120) when trigger (10128) isnot being actuated. FIGS. 100A-100B show an exemplary instrument (10400)that is configured to provide such functionality.

Instrument (10400) of the present example comprises a handle assembly(10410) and a shaft assembly (10450). Handle assembly (10410) comprisesa housing (10412), a pistol grip (10414), and a trigger (10425) that ispivotable toward and away from pistol grip (10414). It should beunderstood that handle assembly (10410) may further include any of theother features of handle assembly (20), any of the other features ofhandle assembly (10120), and/or any other suitable features. Shaftassembly (10450) is selectively rotatable relative to handle assembly(10410) as will be described in greater detail below. Shaft assembly(10450) comprises an outer sheath (10452) and an inner tubular actuatingmember (10454) Inner tubular actuating member (10454) is configured totranslate within outer sheath (10452) to thereby actuate an element ofan end effector (10450) at the distal end of shaft assembly. Forinstance, such an element may be similar to clamp arm (44) or second jaw(10144). It should therefore be understood that the distal end of shaftassembly (10450) may include an end effector like end effector (40), anend effector like end effector (10140), and/or any other suitable kindof end effector. Moreover, shaft assembly (10450) may be configured likeshaft assembly (30), like shaft assembly (10130), or have any othersuitable configuration.

Instrument (10400) further includes a rotation knob (10405), which isfixedly secured to outer sheath (10452). Rotation knob (10405) isrotatably supported by housing (10412) of handle assembly (10410) via anannular flange (10406). In particular, housing (10412) supports rotationknob (10405) via flange (10406) while still permitting rotation knob(10405) to rotate via flange (10406). The proximal end of rotation knob(10405) includes an angular array of proximally presented lockingrecesses (10420), which will be described in greater detail below. Whenrotation knob (10405) is in an unlocked state, the operator may grasprotation knob (10405) and rotate shaft assembly (10450) relative tohandle assembly (10410) via rotation knob (10405). When rotation knob(10405) is in a locked state, shaft assembly (10450) cannot be rotatedrelative to handle assembly (10410).

Trigger (10425) is pivotably mounted to housing (10410) via a pin(10430). Trigger (10425) further comprises an actuating arm (10440) anda locking arm (10435). Actuating arm (10440) is coupled to an actuatingcollar (10415) via pin (10445). Actuating collar (10415) is fixed toinner tubular actuating member (10454). Therefore, closure of trigger(10425) toward pistol grip (10414) rotates actuating arm (10440) via pin(10430), which in turn translates actuating collar (10415) and innertubular actuating member (10454) distally. Additionally, locking arm(10435) pivots about pin (10430) in response to closure of trigger(10425).

As best seen in FIGS. 101A-101B, locking arm (10435) includes a pair ofdistally oriented projections (10436) that are positioned to selectivelyengage locking recesses (10420) of knob (10405). In particular, whentrigger (10425) is in the relaxed state as shown in FIGS. 100A and 101A,projections (10436) are spaced away from recesses (10420), Withprojections (10436) being spaced away from recesses (10420), knob(10405) and shaft assembly (10450) are free to rotate relative to handleassembly (10410). It should also be understood that the movable elementof the end effector that is coupled with inner tubular actuating member(10454) will be in a non-actuated state when trigger (10425) is in therelaxed state as shown in FIGS. 100A and 101A. When trigger (10425) ispivoted toward pistol grip (10414), trigger (10452) reaches the positionshown in FIGS. 100B and 101B. At this stage, inner tubular actuatingmember (10454) is advanced distally via actuating collar (10415),thereby actuating the movable element of the end effector that iscoupled with inner tubular actuating member (10454). In addition,locking arm (10435) is pivoted to a position where projections (10436)are received in recesses (10420). The engagement of projections (10436)in recesses (10420) will effectively lock knob (10405) such that knob(10405) and shaft assembly (10450) are prevented from rotating relativeto handle assembly (10410) when trigger (10425) is in the actuatedposition shown in FIGS. 100B and 101B. When the operator releasestrigger (10425), instrument (10400) returns back to the state shown inFIGS. 100A and 101A. It should therefore be understood that theinstrument (10400) prevents rotation of shaft assembly (10450) relativeto handle assembly (10410) when a movable element of the end effector isbeing actuated; yet permits rotation of shaft assembly (10450) relativeto handle assembly (10410) when the movable element of the end effectoris not being actuated.

In some versions, locking arm (10435) is deformable in the plane alongwhich trigger (10425) pivots; yet is substantially non-deformable alonga path that is transverse to the pivot plane. For instance, locking arm(10435) may be configured such that projections (10436) are received inrecesses (10420) as soon as trigger (10425) pivots through a first rangeof motion toward pistol grip (10414); and such that locking arm (10435)deforms (with projections (10436) still being received in recesses(10420)) as trigger (10425) pivots through a second range of motiontoward pistol grip (10414). In some such versions, trigger (10425) doesnot complete the actuation of the movable element of the end effectoruntil trigger (10425) completes the second range of motion. Thus,locking arm (10435) may prevent rotation of shaft assembly (10450)relative to handle assembly (10410) before the movable element of theend effector is fully actuated. Locking arm (10435) may be configuredsuch that projections (10436) engage recesses (10420) to preventrotation of shaft assembly (10450) relative to handle assembly (10410)at any suitable stage of actuation of the movable element of the endeffector.

In some other variations, locking arm (10435) is pivotably mounted totrigger (10425), such that locking arm (10435) pivots relative totrigger (10425) as trigger (10425) pivots through the second range ofmotion relative to pistol grip (10414). In some such versions, aresilient member may bias locking arm (10435) to engage recesses (10420)as soon as trigger (10425) pivots through the first range of motiontoward pistol grip (10414). Other suitable configurations for lockingarm (10435) will be apparent to those of ordinary skill in the art inview of the teachings herein. Similarly, other suitable relationshipsbetween trigger (10425) and locking arm (10435) will be apparent tothose of ordinary skill in the art in view of the teachings herein. Asyet another merely illustrative alternative, locking arm (104350 may beomitted, and projections (10436) may be secured to actuating collar(10415) or inner tubular actuating member (10454). In versions whereprojections (10436) are secured to inner tubular actuating member(10454), projections (10456) may be incorporated into a locking collarthat is fixedly secured to inner tubular actuating member (10454).

Since knob (10405) has a finite number of recesses (10420), there may beoccasions where the operator actuates trigger (10425) when projections(10436) are not perfectly angularly aligned with corresponding recesses(10420). Thus, projections (10436) and/or recesses (10420) may includeobliquely angled cam features, curved cam features, and/or other kindsof features that are configured to provide self-alignment to therebyfully seat projections (10436) in recesses (10420). In other words, suchself-alignment features may provide whatever further minimal rotation ofshaft assembly (10450) that might be necessary in order to fully seatprojections (10436) in recesses (10420) as trigger (10425) completes arange of pivotal motion toward pistol grip (10414). In such versions, itmay be desirable to maximize the number of recesses (10420) in order tominimize the amount of further rotation that might be required in orderfor self-alignment features to fully seat projections (10436) inrecesses (10420). Minimizing the amount of further rotation that isrequired in order to fully seat projections (10436) in recesses (10420)may minimize the risk of operator frustration, as it will make the finalangular orientation of shaft assembly (10450) as close as possible tothe angular orientation selected by the operator.

C. Exemplary Cam-Driven Clutching Lock for Shaft Assembly

In some instances, it may be desirable to lock rotation of shaftassembly (10130) relative to handle assembly (10120) whenever theoperator is not attempting to rotate knob (10134); and to only unlockrotation of shaft assembly (10130) relative to handle assembly (10120)when the operator is actively rotating knob (10134). To that end, FIGS.102A-102B show a locking mechanism (10500) comprising a rotation knob(10510), and a biased locking member (10563). Rotation knob (10510) issecured to a shaft assembly (10505) and is thereby operable toselectively rotate shaft assembly (10505) relative to a handle assembly(10546). It should be understood that handle assembly (10546) mayfurther include any of the other features of handle assembly (1020), anyof the other features of handle assembly (10120), and/or any othersuitable features. Shaft assembly (10505) may be configured like shaftassembly (30), like shaft assembly (10130), or have any other suitableconfiguration. Moreover, the distal end of shaft assembly (10505) mayinclude an end effector like end effector (40), an end effector like endeffector (10140), and/or any other suitable kind of end effector.

Rotation knob (10510) is rotatably supported by handle assembly (10546)via an annular flange (10506). In particular, handle assembly (10546)supports rotation knob (10510) via flange (10506) while still permittingrotation knob (10510) to rotate via flange (10506). Rotation knob(10510) further comprises a channel (10508), a linear slot (10525), anda V-shaped slot (10520). V-shaped slot (10520) includes a pair ofobliquely angled slot legs. It should be understood that slot (10520)may have various other suitable configurations, such that a “V” shape isnot necessary. Other suitable shapes that slot (10520) may have will beapparent to those of ordinary skill in the art in view of the teachingsherein.

A proximal portion of shaft assembly (10505) that protrudes proximallyfrom knob (10510) comprises an annular array of proximally orientedteeth (10507). Shaft assembly (10505) further includes transverselyoriented pin (10535) that is received in linear slot (10525) of rotationknob (10510). Biased locking member (10563) further comprises a fixedmember (10590), a resilient member (10580), a guide channel (10570), arotation lock base (10562), a rotation lock body (10560), a rotationlock shaft (10540), and a rotation lock pin (10530). Rotation lock body(10560) further comprises a set of distally oriented lock teeth (10561)that are configured to selectively engage teeth (10507) of shaftassembly (10505).

One end of resilient member (10580) is engaged with fixed member(10590), while the other end of resilient member (10580) is engaged withlock base (10562). Fixed member (10590) is fixedly secured to handleassembly (10546). Resilient member (10580) is configured to resilientlybias lock base (10562) distally. In the present example, resilientmember (10580) comprises a coil spring, though it should be understoodthat any other suitable kind of resilient member may be used. Guidechannel (10570) ensures that resilient member (10580) is facing theappropriate direction, preventing resilient member (10580) from bucklinglaterally or otherwise deviating from a path that is parallel to thelongitudinal axis of shaft assembly (10505).

Rotation lock body (10560) is secured to lock base (10562), such thatresilient member (10580) biases rotation lock body (10560) distally vialock base (10562). Rotation lock body (10560) and lock base (10562) areconfigured to translate within handle assembly (10546) but are preventedfrom rotating within handle assembly (10546). For instance, rotationlock body (10560) and/or lock base (10562) may be engaged with handleassembly (10546) via a complementary key and keyway. As another merelyillustrative example, rotation lock body (10560) and/or lock base(10562) may have a non-circular cross-sectional profile that is receivedin a complementary recess or other mounting structure in handle assembly(10546). Other suitable configurations will be apparent to those ofordinary skill in the art in view of the teachings herein.

The proximal end of rotation lock shaft (10540) is engaged with lockbase (10562) such that lock shaft (10540) and lock base (10562)translate with each other relative to handle assembly (10546). However,unlike lock base (10562), lock shaft (10540) is configured to rotaterelative to handle assembly (10546) once lock shaft (10540) has reacheda fully proximal position in an unlocked state, as described in greaterdetail below. The distal end of lock shaft (10540) includes atransversely oriented pin (10530), which is disposed within V-shapedslot (10520). Various suitable ways in which lock shaft (10540) maycoupled with lock base (10562) in order to provide such functionalitywill be apparent to those of ordinary skill in the art in view of theteachings herein. For example, fins/pins could be implemented on lockshaft (10540) or pin (10530), where fins/pins are configured tointerface with short grooves in any fixed element, such as handleassembly (10546), guide channel (10570) or fixed member (10590).Additionally, fins/pins do not necessarily need to be implemented onlock shaft (10540), as lock shaft (10540) could be fixed to lock base(10562) or lock body (10560), in which lock base (10562) or lock body(10560) could have fins/pins configured to rotate lock base (10562) orlock body (10560) once fully proximal, but limiting rotation in a distalposition.

FIG. 102A shows locking mechanism (10500) in a locked state. In thisstate, resilient member (10580) urges lock body (10560) to a distalposition, such that teeth (10561) are engaged with teeth (10507). Pin(10530) is positioned at the vertex of the angle defined by the obliquelegs of slot (10520). With teeth (10561, 10507) engaged, lock body(10560) prevents shaft assembly (10505) from rotating relative to handleassembly (10546). When in a locked state, lock shaft (10540) isconfigured to only translate, so when the operator rotates knob (10510)relative to handle assembly (10546), V-shaped slot (10520) provides acamming action against pin (10530), driving lock body (10560) proximallyvia lock shaft (10540). This moves lock body (10560) to a proximalposition as shown in FIG. 102B, where teeth (10561) are disengaged fromteeth (10507). With teeth (10561, 10507) disengaged, locking mechanism(10500) is now in an unlocked state. When locking mechanism (10500) isin an unlocked state, shaft assembly (10505) is now rotatable relativeto handle assembly (10546). Additionally, as mentioned above, whenlocking mechanism (10500) is in an unlocked state, lock shaft (10540) isnow free to rotate relative to lock base (10562). It should be notedthat, at this stage of operation, pin (10535) of shaft assembly (10505)has reached the end of slot (10525). Thus, further rotation of knob(10510) will cause shaft assembly (10505) to rotate due to engagementbetween pin (10535) and the end of slot (10525). Pin (10535) does notreach the end of slot (10525) until locking mechanism (10500) hasreached the unlocked state shown in FIG. 102B.

Once the operator has achieved the desired rotational position of shaftassembly (10505), the operator may simply release knob (10510). When theoperator releases knob (10510), the bias of resilient member (10580)will urge lock base (10562) and lock body (10560) back to the distalposition shown in FIG. 102A, such that teeth (10561, 10507) will bereengaged to lock the adjusted rotational position of shaft assembly(10505) relative to handle assembly (10546). Pin (10530) will provide acamming action against slot (10525), rotating knob (10510) as pin(10530) and lock shaft (10540) travel distally until pin (10530) againreaches the apex of V-shaped slot (10520) as also shown in FIG. 102A.Locking mechanism (10500) will thus automatically transition back to thelocked state after the operator releases knob (10510).

D. Exemplary Knob-Driven Braking Lock for Shaft Assembly

In some instances, it may be desirable to provide a separate, dedicatedinput feature for the operator to selectively lock and unlock rotationof shaft assembly (10130) relative to handle assembly (10120). To thatend, FIGS. 103A-103B show an exemplary locking mechanism (10600)comprising a rotation knob (10605), a bearing washer (10615), a wavespring (10680), a cam interface plate (10620), and a locking knob(10630). Locking knob (10630) is rotatably fixed to body (10646).Locking feature comprises a locking arm (10631), and a locking body(10632) with a pair of cam lobes (10622, 10633). Cam interface plate(10620) further comprises a concave surface (10622) facing locking knob(10630) and a flat surface facing wave spring (10680).

Rotation knob (10605) is secured to shaft assembly (10608) such thatrotation knob (10605) is operable to rotate shaft assembly (10608)relative to handle assembly (10646). It should be understood that handleassembly (10646) may further include any of the other features of handleassembly (20), any of the other features of handle assembly (10120),and/or any other suitable features. Shaft assembly (10608) may beconfigured like shaft assembly (1030), like shaft assembly (10130), orhave any other suitable configuration. Moreover, the distal end of shaftassembly (10608) may include an end effector like end effector (40), anend effector like end effector (10140), and/or any other suitable kindof end effector.

Rotation knob (10605) further comprises an annular flange (10606) and awave spring channel (10610). Bearing washer (10615) is placed in betweenflange (10606) and wave spring (10680), within wave spring channel(10610). Rotation knob (10605) is rotatably supported by handle assembly(10646) via annular flange (10606). In particular, handle assembly(10646) supports rotation knob (10605) via flange (10606) while stillpermitting rotation knob (10605) to rotate via flange (10606).

The operator may selectively rotate knob (10630) in order to selectivelyprevent or permit rotation of shaft assembly (10608) relative to handleassembly (10646). In particular, FIG. 103A shows locking mechanism(10600) in an unlocked state. In this state, wave spring (10680) is notbeing compressed against bearing washer (10615), such that shaftassembly is not encountering any substantial resistance to rotationrelative to handle assembly (10646). When the operator rotates knob(10630) to transition locking mechanism to a locked state shown in FIG.103B, cam lobe (10633) bears against cam interface plate (10620),driving cam interface plate (10620) distally. This in turn compresseswave spring (10680) against bearing washer (10615), generating africtional braking effect against flange (10606) via bearing washer(10615). This effectively locks rotation of shaft assembly (10608)relative to handle assembly (10646). When the operator wishes to againrotate shaft assembly (10608) relative to handle assembly (10646), theoperator may rotate knob (10630) back to the position shown in FIG.103A, thereby transitioning locking mechanism (10600) back to theunlocked state.

It should be understood that either cam lobe (10633) or cam lobe (10644)may be used to drive cam interface plate (10620) distally, depending onthe direction in which knob (10630) is rotated. In some other versions,knob (10630) is only rotatable in one direction to selectively lockrotation of shaft assembly (10608) relative to handle assembly (10646).Thus, one of cam lobes (10633, 644) may be omitted. It should also beunderstood that wave spring (10680) may be omitted. For instance, caminterface plate (10620) may be positioned and configured to beardirectly against bearing washer (10615). In some variations, lockingmechanism (10600) relies on selective engagement between teeth at thedistal face of cam interface plate (10620) and at the proximal face ofknob (10605) in order to provide selective locking, in a manner similarto locking mechanism (10500). It should also be understood that whileknob (10630) can act as a manual input to lock and unlock rotation ofshaft assembly (10608), knob (10630) could also be configured to provideadditional action, including but not limited to driving articulation ofan articulation section in shaft assembly (10608). Still other suitablevariations will be apparent to those of ordinary skill in the art inview of the teachings herein.

XII. ULTRASONIC SURGICAL INSTRUMENT WITH ARTICULATION JOINT HAVINGINTEGRAL STIFFENING MEMBERS

In some versions of instrument (10) it may be desirable to providefeatures that are configured to selectively provide rigidity toarticulation section (130). For instance, because of various factorssuch as manufacturing tolerances, design limitations, materiallimitations, and/or other factors, some versions of articulation section(130) may be susceptible to some “play” or other small movement of thearticulation section despite being relatively fixed in a given position,such that articulation section (130) is not entirely rigid. It may bedesirable to reduce or eliminate such play in articulation section(130), particularly when articulation section (130) is in a straight,non-articulated configuration. Features may thus be provided toselectively rigidize articulation section (130). Various examples offeatures that are configured to selectively provide rigidity toarticulation section (130) and/or to limit or prevent inadvertentdeflection of end effector (40) will be described in greater detailbelow. Other examples will be apparent to those of ordinary skill in theart according to the teachings herein. It should be understood that theexamples of shaft assemblies and/or articulation sections describedbelow may function substantially similar to shaft assembly (30)discussed above.

It should also be understood that articulation section (130) may stillbe at least somewhat rigid before being modified to include the featuresdescribed below, such that the features described below actually justincrease the rigidity of articulation section (130) rather thanintroducing rigidity to an otherwise non-rigid articulation section(130). For instance, an articulation section (130) in the absence offeatures as described below may be rigid enough to substantiallymaintain a straight or articulated configuration; yet may still provide“play” of about 1 mm or a fraction thereof such that the alreadyexisting rigidity of articulation section (130) may be increased. Thus,terms such as “provide rigidity” and “providing rigidity” shall beunderstood to include just increasing rigidity that is already presentin some degree. The terms “provide rigidity” and “providing rigidity”should not be read as necessarily requiring articulation section (130)to completely lack rigidity before the rigidity is “provided.”

A. Exemplary Collapsible and Expandable Rigidizing member

FIGS. 104A and 104B show shaft assembly (11030) of instrument (11010)described above having a collapsible and expandable tube (11200) addedthereon. As will be described in more detail below, tube (11200) mayfunction to selectively provide rigidity to articulation section (11130)and/or to prevent inadvertent deflection of end effector (11040)relative to outer sheath (11032). Tube (11200) of the present examplecomprises a plurality of annular members (11202) disposed about shaftassembly (11030), including articulation section (11130). As will bedescribed in more detail below, annular members (11202) arelongitudinally translatable along a length of shaft assembly (11030)relative to one another between an expanded configuration (FIG. 104A)and a collapsed configuration (FIG. 104B). Also as will be described inmore detail below, when in the collapsed configuration, annular members(11202) function to provide rigidity to articulation section (11130)and/or to prevent inadvertent deflection of end effector (11040)relative to outer sheath (11032).

A distal-most ring-shaped member (11202A) of tube (11200) is secured toan exterior surface of distal outer sheath (11033) of shaft assembly(11030) distally of articulation section (11130). The remainder ofannular members (11202) of outer sheath (11200) are slidably disposedabout shaft assembly (11030), including articulation section (11130),such that annular members (11202) are translatable along a length shaftassembly (11030) relative to one another. As shown in FIG. 104A, when inthe expanded configuration, annular members (11202), although positionedabout articulation section (11130), are spaced apart from one another.The space between consecutive annular members (11202) allowsarticulation section (11130) to flex to thereby deflect end effector(11040) relative to the longitudinal axis of outer sheath (11032). Asshown in FIG. 104B, annular members (11202) may be translated distallytoward distal-most ring-shaped member (11202A) into the collapsedconfiguration. In the collapsed configuration, annular members (11202)abut one another to form a substantially continuous and rigid tubularmember. Because annular members (11202) abut one another in thecollapsed configuration, annular members (11202) function to providerigidity to articulation section (11130) and/or to prevent inadvertentdeflection of end effector (11040) relative to outer sheath (11032). Ifa user then desires to deflect end effector (11040), annular members(11202) may be moved back to the expanded configuration to permitarticulation section (11130) to flex.

It should be understood that annular members (11202) may be moveddirectly (e.g. by grasping one or more of annular members (11202)directly, etc.) or by providing instrument (11010) with additionalactuation features. For example, handle assembly (11020) of instrument(11010) may be provided with a slidable actuator that is operable tocause independent or concurrent translation of annular members (11202).It should further be understood that tube (11200) may be provided withadditional features that are configured to improve the structuralintegrity of tube (11200) when in the collapsed configuration. Forexample, annular members (11202) may be provided with mating projectionsand recesses or slots that are configured to allow annular members(11202) to further engage one another when in the collapsedconfiguration. Additionally, or alternatively, annular members (11202)may be provided with mating pins and pinholes that are configured toallow annular members (11202) to further engage one another when in thecollapsed configuration.

It should also be understood that annular members (11202) may betethered to each other by wires, cables, or other kinds of flexiblemembers. In such versions, when the proximal-most annular member (11202)is pulled proximally from the position shown in FIG. 104B to theposition shown in FIG. 104A, such tethers may communicate the proximalmotion from the proximal-most annular member (11202) to the rest of theannular members (11202), thereby pulling the rest of the proximalmembers from the positions shown in FIG. 104B to the positions shown inFIG. 104A. Such tethers may have a length selected to provide thespacing shown in FIG. 104A; while also having the flexibility to allowannular members (11202) to reach the positions shown in FIG. 104B.Various suitable ways in which annular members (11202) may beconfigured, actuated, and coupled with each other will be apparent tothose of ordinary skill in the art in view of the teachings herein.

B. Exemplary Inflatable and Deflatable Rigidizing member

FIGS. 105-106C show shaft assembly (11030) of instrument (11010)described above having an inflatable and deflatable balloon (11220)secured thereto. As will be described in more detail below, balloon(11220) may function to selectively provide rigidity to articulationsection (11130) and/or to prevent inadvertent deflection of end effector(11040) relative to outer sheath (11032). Balloon (11220) of the presentexample comprises a tubular body (11222) disposed about shaft assembly(11030), including articulation section (11130). Fluid is provided totubular body (11222) via a tube (11224) which extends along a length ofshaft assembly (11030) adjacent an exterior surface of outer sheath(11030). As will be described in more detail below, tube (11224)functions to provide fluid to or to remove fluid from tubular body(11222) so as to transition balloon (11220) between a deflated state(FIGS. 106A and 106C) and an inflated state (FIG. 106B). Also as will bedescribed in more detail below, when in the inflated state, balloon(11220) functions to provide rigidity to articulation section (11130)and/or to prevent inadvertent deflection of end effector (11040)relative to outer sheath (11032) when balloon (11220) is in an inflatedstate.

Tubular body (11222) is disposed about shaft assembly (11030), includingarticulation section (11130). In the present example, tubular body(11222) is formed of a flexible yet non-extensible material. Varioussuitable materials that may be used to form tubular body (11222) will beapparent to those of ordinary skill in the art in view for the teachingsherein. A distal end (11222A) of tubular body (11222) is secured to anexterior surface of distal outer sheath (11033) of shaft assembly(11030) distally of articulation section (11130). A proximal end(11222B) of tubular body (11222) is secured to an exterior surface ofouter sheath (11032) of shaft assembly (11030) proximally ofarticulation section (11130). Thus, as shown in FIG. 106A, tubular body(11222) completely encompasses articulation section (11130). As shown inFIGS. 106A and 106C, when in the deflated state, tubular body (11222),although positioned about articulation section (11130), remains flexibleenough to allow articulation section (11130) to flex to thereby deflectend effector (11040) relative to outer sheath (11032). As shown in FIG.106B, when in the inflated state, tubular body (11222) becomes morerigid and functions to provide rigidity to articulation section (11130)and/or to prevent inadvertent deflection of end effector (11040)relative to outer sheath (11032). If a user then desires to deflect endeffector (11040), tubular body (11222) may be deflated to permitarticulation section (11130) to flex.

In the present example, the fluid communicated to tubular body (11222)comprises saline, though it should be understood that any other suitablefluid may be used. There are various ways in such fluid (e.g., saline,etc.) may be provided to tubular body (11222). By way of example only, afluid syringe (not shown) may be coupled with a proximal end of tube(11224) to thereby provide fluid to and to remove fluid from tubularbody (11222). It should also be understood that, when fluid iscommunicated to tubular body (11222), the non-extensibility of tubularbody may enable tubular body (11222) to be inflated to pressures thatmake tubular body (11222) substantially rigid, thereby effectivelyrigidizing articulation section (11130). Various suitable fluidpressures and volumes that may be used for balloon (11220) will beapparent to those of ordinary skill in the art in view of the teachingsherein.

C. Exemplary Accordion-Like Rigidizing member

FIGS. 107-111B show shaft assembly (11030) of instrument (11010)described above having an accordion-like rigidizing member (11240)incorporated therein. As will be described in more detail below,rigidizing member (11240) may function to selectively provide rigidityto articulation section (11130) and/or to prevent inadvertent deflectionof end effector (11040) relative to outer sheath (11032). As best seenin FIGS. 108A and 108B, rigidizing member (11240) of the present examplecomprises a plurality of bellows (11242) linked to one another along alength of rigidizing member (11240). As will be described in more detailbelow, rigidizing member (11240) is longitudinally translatable along alength of shaft assembly (11030) so as to transition bellows (11242)between a contracted configuration (FIG. 108A) and an expandedconfiguration (FIG. 108B). Also as will be described in more detailbelow, when in the contracted configuration, bellows (11242) ofrigidizing member (11240) function to provide rigidity to articulationsection (11130) and/or to prevent inadvertent deflection of end effector(11040) relative to outer sheath (11032). By way of example only,rigidizing member (11240) may be formed by a series of linkages thatpivotably define bellows (11242). Use of the term “bellows” shouldtherefore be understood to not necessarily require a vessel that definesa variable capacity. Various suitable ways in which rigidizing member(11240) may be configured will be apparent to those of ordinary skill inthe art in view of the teachings herein.

As shown in FIG. 107, shaft assembly (11030) of the present examplecomprises a plurality of couplers (11230) pivotably linked to oneanother via a plurality of pins (11232). Couplers (11230) are disposedabout shaft assembly (11030), including articulation section (11130). Adistal-most coupler (11230A) of couplers (11230) is secured to anexterior surface of distal outer sheath (11033) of shaft assembly(11030) distally of articulation section (11130). A proximal-mostcoupler (11230B) of couplers (11230) is secured to an exterior surfaceof outer sheath (11032) of shaft assembly (11030) proximally ofarticulation section (11130). Thus, as shown in FIG. 107, couplers(11230), when linked to one another, completely encompass articulationsection (11130). Each coupler (11230) includes a pair of angled surfaces(11234) which, when couplers (11230) are linked to one another, forms aplurality of V-shaped pockets (11236) in a side surface rigidizingmember (11240). Pockets (11236) are configured to provide clearancebetween couplers (11230) to allow couplers (11230) to pivot relative toeach other about pins (11232) as articulation section (11130) isarticulated. Pockets (11236) are also configured to receive bellows(11242) as described in greater detail below. While pockets (11236) areshown on only one side of couplers (11230) in this example, it should beunderstood that pockets (11236) may be provided on both sides ofcouplers (11230) if desired. Such a configuration may permit orfacilitate articulation of articulation sections in two oppositedirections relative to the longitudinal axis of outer sheath (11032).

As shown in FIG. 110A, with bellows (11242) in the contractedconfiguration, bellows (11242) of rigidizing member (11240) areconfigured to extend through V-shaped pockets (11236) and bear againstangled surfaces (11234) of couplers (11230) to thereby provide rigidityto articulation section (11130) and/or to prevent inadvertent deflectionof end effector (11040) relative to outer sheath (11032). As shown inFIG. 110B, rigidizing member (11240) is drawn proximally so as totransition bellows (11242) to the expanded configuration. Thistransitioning of bellows (11242) draws bellows (11242) inwardly fromV-shaped pockets (11236) such that bellows (11242) no longer bearagainst angled surfaces (11234) of couplers (11230) and such thatarticulation section (11130) may flex to thereby deflect end effector(11040) relative to outer sheath (11032).

In some versions of instrument (11010), rigidizing member (11240) may becoupled with rotation knob (11120) such that rotation of rotation knob(11120) causes concurrent articulation of articulation section (11130)and translation of rigidizing member (11240). For instance, as shown inFIGS. 111A and 111B, the proximal end of rigidizing member (11240) maybe coupled with rotation knob (11120) via a slot (11117) formed in aside of first hollow cylindrical portion (11112) of housing (11110). Thedistal end of rigidizing member (11240) may be fixedly secured to distalouter sheath (11033) or some other structure that is distal toarticulation section (11130). Thus, as rotation knob (11120) is rotatedin a first direction from the position shown in FIG. 111A to theposition shown in FIG. 111B to cause articulation of articulationsection (11130), rigidizing member (11240) is concurrently drawnproximally so as to transition bellows (11242) from the configurationshown in FIG. 110A to the configuration shown in FIG. 110B. This causesbellows (11242) to disengage angled surfaces (11234), thus allowingarticulation section (11130) to flex to thereby deflect end effector(11040) relative to outer sheath (11032).

As rotation knob (11120) is rotated in the opposite direction from theposition shown in FIG. 111B to the position shown in FIG. 111A to returnarticulation section (11130) to back toward the straight configuration,rigidizing member (11240) is concurrently driven distally so as totransition bellows (11242) back from the configuration shown in FIG.110B to the configuration shown in FIG. 110A. This causes bellows(11242) to re-engage angled surfaces (11234), thus providing rigidity toarticulation section (11130) and/or preventing inadvertent deflection ofend effector (11040) relative to outer sheath (11032). It shouldtherefore be understood that articulation section (11130) may beautomatically rigidized upon reaching a straight configuration.

D. Exemplary Pegged Rigidizing member

FIGS. 112-114B show a rigidizing member (11260) that may be used in lieuof rigidizing member (11240) discussed above. As best seen in FIGS. 112and 113, rigidizing member (11260) of the present example comprises anelongate shaft (11262), having a rectangular cross-section, and aplurality of pegs (11264) extending transversely from a side surface ofshaft (11262). As will be described in more detail below, rigidizingmember (11260) is laterally translatable within an interior space ofshaft assembly (11030) between a first position (FIG. 114A) and a secondposition (FIG. 114B). Also as will be described in more detail below,when in the first position, pegs (11264) of rigidizing member (11260)function to provide rigidity to articulation section (11130) and/or toprevent inadvertent deflection of end effector (11040) relative to outersheath (11032).

As shown in FIGS. 114A and 114B, rigidizing member (11260) is configuredto be positioned within an interior space of shaft assembly (11030),including articulation section (11130). As shown in FIG. 114A, withrigidizing member (11260) positioned within the interior space of shaftassembly (11030) in the first position, pegs (11264) are configured toextend through V-shaped pockets (11236) and bear against (or at leastcontact) angled surfaces (11234) of couplers (11230) to thereby providerigidity to articulation section (11130) and/or to prevent inadvertentdeflection of end effector (11040) relative to outer sheath (11032). Asshown in FIG. 114B, rigidizing member (11260) is translated laterallyinwardly into the second position to thereby draw pegs (11264) inwardlyfrom V-shaped pockets (11236) such that pegs (11264) no longer bearagainst (or otherwise contact) angled surfaces (11234) of couplers(11230). With pegs (11264) moved out of V-shaped pockets (11236),articulation section (11130) is free to flex to thereby deflect endeffector (11040) relative to outer sheath (11032). Various suitable waysin which rigidizing member (11260) may be actuated between the positionsshown in FIGS. 114A and 114B will be apparent to those of ordinary skillin the art in view of the teachings herein.

E. Exemplary Variable-Thickness Rigidizing Member and Couplers

FIGS. 115-116C show a variable-thickness rigidizing member (11280) thatmay be incorporated into articulation section (11130) of shaft assembly(11030) of instrument (11010). As will be described in more detailbelow, rigidizing member (11280) may function to selectively providerigidity to articulation section (11130) and/or to prevent inadvertentdeflection of end effector (11040) relative to outer sheath (11032). Asbest seen in FIG. 115, rigidizing member (11280) of the present examplecomprises a plurality of flanges (11282) linked to one another by aplurality of flexible rods (11284), which are positioned betweenconsecutive flanges (11282). It should be understood that rods (11284)may be substituted with wires, cables, or any other suitable kind offlexible member. As will be described in more detail below, rigidizingmember (11280) is longitudinally translatable along a length of shaftassembly (11030) so as to transition flanges (11282) between a firstposition (FIG. 116A) and a second position (FIGS. 116B and 116C). Alsoas will be described in more detail below, when in the first position,flanges (11282) of rigidizing member (11280) function to providerigidity to articulation section (11130) and/or to prevent inadvertentdeflection of end effector (11040) relative to outer sheath (11032).

In the present example a modified version of shaft assembly (11030)comprises a plurality of couplers (11290) that are pivotably linked toone another via a plurality of pins (11292). Couplers (11290) aredisposed about shaft assembly (11030), including articulation section(11130). A distal-most coupler (11290A) of couplers (11290) is securedto an exterior surface of distal outer sheath (11033) of shaft assembly(11030) distally of articulation section (11130). A proximal-mostcoupler (11290B) of couplers (11290) is secured to an exterior surfaceof outer sheath (11032) of shaft assembly (11030) proximally ofarticulation section (11130). Thus, when linked to one another via pins(11292), couplers (11290) completely encompass articulation section(11130). As mentioned above, couplers (11290) are pivotably linked toone another via a plurality of pins (11292) such that couplers (11290)pivot about a plurality of axes defined by pins (11292). Pins (11292),which pivotably link couplers (11290) to one another, are aligned suchthat articulation section (11130) may flex along a plane (P1) orientedperpendicular to the axes of rotation of pins (11292).

As shown in FIGS. 116A-116C, rigidizing member (11280) is configured tobe positioned within an interior space of shaft assembly (11030),including articulation section (11130), inside the assembly formed bycouplers (11290). Rigidizing member (11280) is oriented such thatflanges (11282) are substantially parallel to plane (P1) andperpendicular to the axes of rotation of pins (11292). As shown in FIG.116A, with flanges (11282) in the first position, flanges (11282) ofrigidizing member (11280) are positioned such that each flange (11282)extends between a space defined by consecutive couplers (11290) and suchthat pins (11292) are positioned above and below an intermediate portionof flanges (11282). Because flanges (11282) are positioned at the jointsof couplers (11290), flanges (11282) prevent couplers (11290) fromflexing at those joints. This further prevents flexing at articulationsection. Thus, when rigidizing member (11280) is in the position shownin FIG. 116A, the assembly formed by rigidizing member (11280) andcouplers (11290) prevents bending of articulation section (11130) andeffectively rigidizes articulation section (11130).

As shown in FIGS. 116B and 116C, rigidizing member (11280) is translatedproximally so as to move flanges (11282) away from the joints ofcouplers (11290) and to position flexible rods (11284) at the joints ofcouplers (11290). This positioning enables couplers (11290) to pivot atthe joints. With couplers (11290) being enabled to pivot, and withflexible rods (11284) being enabled to flex, articulation section(11130) is thereby enabled to articulate as shown in FIG. 116C. Varioussuitable ways in which rigidizing member (11280) may be actuated betweenthe position shown in FIG. 116A and the positions shown in FIGS.116B-116C will be apparent to those of ordinary skill in the art in viewof the teachings herein.

F. Exemplary Variable-Thickness Rigidizing Member

FIGS. 117-122C show shaft assembly (11030) of instrument (11010)described above having a variable-thickness rigidizing member (11300)incorporated therein. As will be described in more detail below,rigidizing member (11300) may function to selectively provide rigidityto articulation section (11130) and/or to prevent inadvertent deflectionof end effector (11040) relative to outer sheath (11032). As best seenin FIG. 118, rigidizing member (11300) of the present example comprisesa plurality of flanges (11302) linked to one another by a plurality offlexible rods (11304) that are positioned between consecutive flanges(11302). It should be understood that rods (11304) may be substitutedwith wires, cables, or any other suitable kind of flexible member. Asshown in FIG. 119, flanges (11302) of the present example have arectangular cross-section. In some other versions, flanges (11302) havea circular segment cross-section as shown in FIG. 120. Alternatively,flanges (11302) may have any other suitable cross-section as will beappreciated by one of ordinary skill in the art in view of the teachingsherein. As will be described in more detail below, rigidizing member(11300) is longitudinally translatable along a length of shaft assembly(11030) so as to transition flanges (11302) between a first position(FIG. 122A) and a second position (FIGS. 122B and 122C). As will also bedescribed in more detail below, when rigidizing member (11300) is in thefirst position, flanges (11302) of rigidizing member (11300) function toprovide rigidity to articulation section (11130) and/or to preventinadvertent deflection of end effector (11040) relative to outer sheath(11032).

As shown in FIG. 121, shaft assembly (11030) of the present example,including articulation section (11130), defines a channel (11310) in atop portion of ribbed body portions (11132, 11134) of articulationsection (11130). Channel (11310) is configured to slidably receiverigidizing member (11300) such that rigidizing member (11300) islongitudinally translatable within channel (11310) along a length ofshaft assembly (1130).

As shown in FIGS. 122A-122C, rigidizing member (11300) is configured tobe positioned within an interior space of shaft assembly (11030),including articulation section (11130). Rigidizing member (11300) isoriented such that flanges (11302) are substantially parallel to a plane(P2) along which articulation member (11130) is configured to flex. Asshown in FIG. 122A, with flanges (11302) in the first position, flanges(11302) of rigidizing member (11300) are positioned such that eachflange (11302) extends between the spaces between consecutive retentioncollars (11133). Because of the orientation and position of flanges(11302) in this state, and because of the width of flanges (11302),flanges (11302) block relative movement of retention collars (11133)along plane (P2). Rigidizing member (11300) thus prevents bending ofarticulation section (11130) and effectively rigidizes articulationsection (11130).

As shown in FIGS. 122B and 122C, rigidizing member (11300) is translatedproximally so as to position flanges (11302) away from the spacesbetween consecutive retention collars (11133) and to position flexiblerods (11304) between the spaces between consecutive retention collars(11133). This positioning enables retention collars (11133) to moverelative to each other along plane (P2). With such movement of collars(11133) enabled, and with flexible rods (11304) being enabled to flex,articulation section (11130) is thereby enabled to articulate as shownin FIG. 122C. Various suitable ways in which rigidizing member (11300)may be actuated between the position shown in FIG. 122A and thepositions shown in FIGS. 122B-122C will be apparent to those of ordinaryskill in the art in view of the teachings herein.

G. Exemplary Rigidizing Sleeve Member

FIGS. 123-125C show an exemplary rigidizing sleeve member (11320). Aswill be described in more detail below, rigidizing sleeve member (11320)may function to selectively provide rigidity to articulation section(11130) and/or to prevent inadvertent deflection of end effector (11040)relative to outer sheath (11032). As best seen in FIG. 123, rigidizingmember (11320) of the present example comprises a proximalsemi-circular-cylindrical portion (11322) and a distalsemi-circular-cylindrical portion (11324). Portions (11322, 11324) arecoupled together via a flexible rod (11326). Rod (11326) provideslateral flexibility yet has sufficient column strength to provideeffective actuation of rigidizing sleeve member (11320) as describedbelow. It should be understood that rod (11326) may be substituted witha band or any other suitable kind of flexible member. Cylindricalportions (11322, 11324) are sized to receive and selectively coupleabout shaft assembly (11030) in a snap-fit manner. As will be describedin more detail, however, sleeve member (11320) remains able to translatelongitudinally along a length of shaft assembly (11030) so as totransition distal cylindrical portion (11324) between a first position(FIG. 125A) and a second position (FIGS. 125B and 125C). Also as will bedescribed in more detail below, when sleeve member (11320) is in thefirst position, distal cylindrical portion (11324) of sleeve member(11320) functions to provide rigidity to articulation section (11130)and/or to prevent inadvertent deflection of end effector (11040)relative to outer sheath (11032).

As best seen in FIG. 123, proximal cylindrical portion (11322) comprisesa pair of flanges (11328) extending from opposing sides of an exteriorsurface of proximal cylindrical portion (11322). A user may engageflanges (11328) to assist the user in positioning proximal cylindricalportion (11322) about and removing proximal cylindrical portion (11322)from shaft assembly (11030). Alternatively, any other suitable featuresmay be used to facilitate manipulation of proximal cylindrical portion(11322). As shown in FIG. 124, distal cylindrical portion (11324)comprises a plurality of rectangular projections (11327) extendinginwardly from an interior surface of distal cylindrical portion (11324).

As shown in FIGS. 125A-125C, and as discussed above, distal cylindricalportion (11324) is configured to be positioned about shaft assembly(11030), in particular, about articulation section (11130). As shown inFIG. 125A, with distal cylindrical portion (11324) in the firstposition, projections (11327) of distal cylindrical portion (11324) arepositioned such that each projection (11327) is positioned within acorresponding space defined between consecutive retention collars(11133) such that projections (11327) abut consecutive retention collars(11133). Because projections (11327) abut consecutive retention collars(11133) when sleeve member (11320) is in the first position, projections(11327) function to provide rigidity to articulation section (11130)and/or to prevent inadvertent deflection of end effector (11040)relative to outer sheath (11032) by preventing movement of retentioncollars (11133) relative to each other.

As shown in FIGS. 125B and 125C, rigidizing sleeve member (11320) istranslated proximally so as to draw projections (11327) from the spacesdefined by consecutive retention collars (11133) and so as to positionprojections (11327) adjacent an exterior surface of retention collars(11133). With sleeve member (11320) in this position, the space betweenconsecutive retention collars (11133) allows articulation section(11130) to flex to thereby deflect end effector (11040) relative toouter sheath (11032) as shown in FIG. 125C.

Distal cylindrical portion (11324) is formed of a resilient materialthat enables projections (11327) to deflect outwardly from the positionshown in FIG. 125A to the position shown in FIGS. 125B and 125C. Theresilient properties of distal cylindrical portion (11324) also causeprojections (11327) to snap back into the spaces defined betweenconsecutive retention collars (11133) when sleeve member (11320) isadvanced distally back to the position shown in FIG. 125A. In thepresent example, sleeve member (11320) may be returned to the positionshown in FIG. 125A after articulation section (11130) has been returnedto a straight, non-articulated configuration. Also in the presentexample, sleeve member (11320) is translated between the distal position(FIG. 125A) and the proximal position (FIGS. 125B and 125C) by anoperator grasping proximal cylindrical portion (11322) and therebysliding sleeve member (11320) along shaft assembly (11030). Othersuitable ways in which sleeve member (11320) may be actuated will beapparent to those of ordinary skill in the art in view of the teachingsherein.

H. Exemplary C-Channel Rigidizing member

FIGS. 126-130B show another exemplary rigidizing member (11340). As willbe described in more detail below, rigidizing member (11340) mayfunction to selectively provide rigidity to articulation section (11130)and/or to prevent inadvertent deflection of end effector (11040)relative to outer sheath (11032). As best seen in FIG. 126, rigidizingmember (11340) of the present example comprises a plurality of C-channelmembers (11342) linked to one another by a plurality of flexible rods(11344), which are positioned between consecutive C-channel members(11342). It should be understood that rods (11344) may be substitutedwith wires, cables, or any other suitable kind of flexible member. Aswill be described in more detail below, rigidizing member (11340) isconfigured to translate longitudinally along a length of shaft assembly(11030) so as to transition C-channel members (11342) between a firstposition (FIG. 129A) and a second position (FIGS. 129B and 129C). Alsoas will be described in more detail below, when rigidizing member(11340) is in the first position, C-channel members (11342) ofrigidizing member (11340) function to provide rigidity to articulationsection (11130) and/or to prevent inadvertent deflection of end effector(11040) relative to outer sheath (11032).

As shown in FIGS. 129A-129C, C-channel members (11342) are configured tobe positioned about shaft assembly (11030), in particular, aboutarticulation section (11130). As shown in FIG. 129A, with rigidizingmember (11340) in the first position, C-channel members (11342) arepositioned such that each C-channel member (11342) is positioned withina corresponding space defined between consecutive retention collars(11133) such that C-channel members (11342) abut consecutive retentioncollars (11133). Because C-channel members (11342) abut consecutiveretention collars (11133) when rigidizing member (11340) is in the firstposition, C-channel members (11342) function to provide rigidity toarticulation section (11130) and/or to prevent inadvertent deflection ofend effector (11040) relative to outer sheath (11032) by preventingmovement of retention collars (11133) relative to each other.

As shown in FIGS. 129B and 129C, rigidizing member (11340) is translatedproximally so as to draw C-channel members (11342) from the spacesdefined between consecutive retention collars (11133) and so as toposition C-channel members (11342) adjacent an exterior surface ofretention collars (11133). With rigidizing member (11340) in thisposition, the space between consecutive retention collars (11133) allowsarticulation section (11130) to flex to thereby deflect end effector(11040) relative to outer sheath (11032) as shown in FIG. 129C.

Rigidizng member (11340) is formed of a resilient material that enablesC-channel members (11342) to deform and deflect outwardly from theposition shown in FIG. 129A to the position shown in FIGS. 129B and129C. The resilient properties of C-channel members (11342) also causeC-channel members (11342) to snap back into the spaces defined betweenconsecutive retention collars (11133) when rigidizing member (11340) isadvanced distally back to the position shown in FIG. 129A. In thepresent example, rigidizing member (11340) may be returned to theposition shown in FIG. 129A after articulation section (11130) has beenreturned to a straight, non-articulated configuration. Various suitableways in which rigidizing member (11340) may be actuated will be apparentto those of ordinary skill in the art in view of the teachings herein.

Although the example discussed above is provides just a singlerigidizing member (11340), on just one side of articulation section(11130), it should be understood that two or more rigidizing members(11340) may be used. For instance, as shown in FIGS. 130A and 130B, apair of rigidizing members (11340) may be positioned on opposite lateralsides of articulation section (11130) to provide rigidity toarticulation section (11130) and/or to prevent inadvertent deflection ofend effector (11040) relative to outer sheath (11032) in multipledirections.

I. Exemplary Rigidizing Clip Member

FIGS. 131-132B show an exemplary rigidizing clip member (11360). As willbe described in more detail below, rigidizing clip member (11360) mayfunction to selectively provide rigidity to articulation section (11130)and/or to prevent inadvertent deflection of end effector (11040)relative to outer sheath (11032). As best seen in FIG. 131, rigidizingclip member (11360) of the present example comprises asemi-circular-cylindrical body (11362). A plurality of slots (11364)formed in opposing side surfaces of cylindrical body (11362) separate aplurality of tabs (11366). As shown in FIGS. 132A and 132B, rigidizingclip member (11360) is configured to be positioned about shaft assembly(11030), in particular, about articulation section (11130).

As shown in FIG. 132A, spaces defined between consecutive retentioncollars (11133) provide clearance allowing articulation section (11130)to flex to thereby deflect end effector (11040) relative to outer sheath(11032). As shown in FIG. 132B, with rigidizing clip member (11360)positioned about articulation section (11130), tabs (11366) arepositioned such that each tab (11366) is positioned within the spacedefined by consecutive retention collars (11133). Tabs (11366) abutconsecutive retention collars (11133) in this state. Because tabs(11366) abut consecutive retention collars (11133), tabs (11366)function to provide rigidity to articulation section (11130) and/or toprevent inadvertent deflection of end effector (11040) relative to outersheath (11032) by preventing movement of retention collars (11133)toward one another. It should be understood that clip member (11360) maybe formed of a resilient material such that clip member (11360) may beremovably secured to articulation section (11130) through a snap fit.Alternatively, clip member (11360) may be removably secured toarticulation section (11130) in any other suitable fashion.

J. Exemplary Dual Structural Bands

FIGS. 133A-136B show a modified version of shaft assembly (11030) ofinstrument (11010) described above having a pair of overlappingarticulation bands (11380, 11390). As will be described in more detailbelow, articulation bands (11380, 11390) may function to providerigidity to articulation section (11130) and/or to prevent inadvertentdeflection of end effector (11040) relative to outer sheath (11032). Asbest seen in FIG. 134, articulation band (11380) comprises an elongatestrip (11382) having a plurality of circular openings (11384) formedtherein to provide “weak spots” along the length of strip (11382).Circular openings (11384) are spaced apart from one another, and provideflexibility to articulation band (11380) at circular openings (11384).As best seen in FIG. 135, articulation band (11390) comprises anelongate strip (11392) having a plurality of opposing rectangularrecesses (11394) formed therein to provide “weak spots” along the lengthof strip (11392). Rectangular recesses (11394) are spaced apart from oneanother, and provide flexibility to articulation band (11390) atrectangular recesses (11394). The spacing of recesses (11394)corresponds to the spacing of openings (11384).

As shown in FIGS. 133A and 133B, articulation bands (11380, 11390) arepositioned within an interior space of shaft assembly (11030), includingarticulation section (11130). One set of articulation bands (11380,11390) is positioned on one side of waveguide (11180); while another setof articulation bands (11380, 11390) is positioned on the other side ofwaveguide (11180). Articulation bands (11380, 11390) are longitudinallytranslatable relative to one another between a first configuration (FIG.136A) and a second configuration (FIG. 136B). As shown in FIG. 136A, inthe first configuration, articulation bands (11380, 11390) overlap oneanother in an arrangement such that circular openings (11384) ofarticulation band (11380) are offset from rectangular recesses (11394)of articulation band (11390). With these “weak spots” of articulationbands (11380, 11390) offset from one another, the remaining “strongspots” of articulation bands (11380, 11390) accommodate for the “weakspots” and prevent articulation bands (11380, 11390) from flexing.Articulation bands (11380, 11390) thus cooperate to provide rigidity toarticulation section (11130) and/or prevent inadvertent deflection ofend effector (11040) relative to outer sheath (11032) when articulationbands (11380, 11390) are arranged as shown in FIG. 136A. In the presentexample, articulation bands (11380, 11390) are positioned in thisarrangement when articulation section (11130) is in a straight,non-articulated configuration as shown in FIG. 133A.

As shown in FIG. 136B, in the second configuration, articulation bands(11380, 11390) overlap one another in an arrangement such that circularopenings (11384) of articulation band (11380) align with rectangularrecesses (11394) of articulation band (11390). With these “weak spots”of articulation bands (11380, 11390) aligned, articulation bands (11380,11390) may flex to thereby allow articulation section (11130) to flex tothereby deflect end effector (11040) relative to outer sheath (11032).In other words, articulation bands (11380, 11390) cooperate to provideflexibility to articulation section (11130) when articulation bands(11380, 11390) are arranged as shown in FIG. 136B. While the “weakspots” of articulation bands (11380, 11390) are formed as circularopenings (11384) and rectangular recesses (11394) in the presentexample, it should be understood that the “weak spots” may have anyother suitable configurations. Various suitable alternativeconfigurations for “weak spots” will be apparent to those of ordinaryskill in the art in view of the teachings herein.

Articulation control assembly (11100) may be readily modified to providecoordinated movement of articulation bands (11380, 11390). For instance,in one merely illustrative example, articulation control assembly(11100) is configured such that knob (11120) is rotatable through tworanges of motion from a neutral position where articulation section(11130) is in a straight, non-articulated configuration as shown in FIG.133A. With knob (11120) in the neutral position, articulation bands(11380, 11390) are in the arrangement shown in FIG. 136A, such thatarticulation bands (11380, 11390) rigidize articulation section (11130),with articulation section (11130) being in the straight, non-articulatedconfiguration. When knob (11120) is rotated through a first range ofmotion from the neutral position, articulation control assembly (11100)drives a first articulation band (11380, 11390) in each pair ofarticulation bands (11380, 11390) relative to a second articulation band(11380, 11390) in that pair. The second articulation band (11380, 11390)remains stationary during this first range of motion of knob (11120).

When knob (11120) completes the first range of motion, each pair ofarticulation bands (11380) is transitioned to the configuration shown inFIG. 136B, such that articulation bands (11380, 11390) are arranged toprovide flexibility. When the operator then rotates knob (11120) througha second range of motion after completing the first range of motion,articulation control assembly (11100) drives a both articulation bands(11380, 11390) of one pair together in a first longitudinal direction,while simultaneously driving both articulation bands (11380, 11390) ofthe other pair together in a second longitudinal direction. The pairs ofarticulation bands (11380, 11390) thus cooperate to drive articulationas knob (11120) is rotated through the second range of motion.

When the operator wishes to subsequently transition articulation section(11130) back to a straight, non-articulated state, the operator maysimply reverse rotation of knob (11120). During this reversal, the pairsof articulation bands (11380, 11390) will again cooperate to drivearticulation section (11130) back to the straight, non-articulatedstate. Once articulation section (11130) reaches the straight,non-articulated state, knob (11120) will transition from the secondrange of motion back to the first range of motion as knob (11120) isfurther rotated. As knob (11120) is rotated back through the first rangeof motion toward the neutral position, articulation control assembly(11100) again drives a first articulation band (11380, 11390) in eachpair of articulation bands (11380, 11390) relative to a secondarticulation band (11380, 11390) in that pair. The second articulationband (11380, 11390) remains stationary during this first range of motionof knob (11120). Once knob (11120) reaches the neutral position again,articulation bands (11380, 11390) are again returned to the arrangementshown in FIG. 136A, such that articulation bands (11380, 11390) againrigidize articulation section (11130). Various structures and featuresthat may be incorporated into articulation control assembly (11100) inorder to provide the above described operation will be apparent to thoseof ordinary skill in the art in view of the teachings herein.

While knob (11120) is used in the present example, it should beunderstood that any other suitable kind of actuator may be used,including but not limited to a slider, a lever, a dial, etc. Inaddition, in the present example knob (11120) is operable to bothselectively rigidize articulation section (11130) (as knob (11120) isrotated through the first range of motion) and to drive articulation ofarticulation section (11130) (as knob (11120) is rotated through thesecond range of motion). In some other versions, two separate actuatorsare used—one actuator to selectively rigidize articulation section(11130) and another actuator to drive articulation of articulationsection (11130).

It should also be understood that any other example described herein forselectively rigidizing articulation section (11130) may also be coupledwith a modified version of articulation control assembly (11100) asdescribed above. In other words, any other example described herein forselectively rigidizing articulation section (11130) may be coupled witha knob (11120) that rotates through two ranges of motion—a first rangeof motion to selectively rigidize articulation section (11130) and asecond range of motion to drive articulation of articulation section(11130). Similarly, any other kind of actuator may be used, includingbut not limited to a slider, a lever, a dial, etc. Such alternativeactuators may also be moved through two different ranges of motion toselectively rigidize articulation section (11130) (during a first rangeof motion of the actuator) and to drive articulation of articulationsection (during a second range of motion of the actuator). Furthermore,any other example described herein for selectively rigidizingarticulation section (11130) may also be coupled with two separateactuators—one actuator to selectively rigidize articulation section(11130) and another actuator to drive articulation of articulationsection (11130). Various suitable ways in which these exemplaryalternatives may be incorporated into the various examples describedherein will be apparent to those of ordinary skill in the art in view ofthe teachings herein.

K. Exemplary Rigidizing Tubular Member

FIG. 137 shows a modified version of shaft assembly (11030) ofinstrument (11010) having a tubular member (11400) that is configured toselectively rigidize. As will be described in more detail below, tubularmember (11400) may function to selectively provide rigidity toarticulation section (11130) and/or to prevent inadvertent deflection ofend effector (11040) relative to outer sheath (11032). Tubular member(11400) comprises hollow-cylindrical body (11402) filled withmagnetorheological fluid (MR fluid) (11404). Cylindrical body (11402) ispositioned about shaft assembly (11030) and encompasses articulationsection (11130). Cylindrical body (11402) is capped at a distal end anda proximal end by a pair of magnets (11406). In the present example,magnets (11406) comprise electromagnets, such that magnets (11406) maybe selectively activated (and thereby be selectively magnetized) byapplication of an electric current to magnets (11406). A distal magnet(11406A) of magnets (11406) is secured to an exterior surface of distalouter sheath (11033) of shaft assembly (11030) distally of articulationsection (11130). A proximal magnet (11406B) of magnets (11406) issecured to an exterior surface of outer sheath (11032) of shaft assembly(11030) proximally of articulation section (11130).

Magnets (11406) are in direct contact with MR fluid (11404) such thatmagnets (11406) may function to selectively magnetize MR fluid (11404)based on selective activation of magnets (11406). Prior to magnetizingMR fluid (11404), cylindrical body (11402) of tubular member (11400) isoperable to flex to thereby allow articulation section (11130) to flexto thereby deflect end effector (11040) relative to outer sheath(11032). Once MR fluid (11404) is magnetized via activation of magnets(11406), however, MR fluid (11404) becomes substantially rigid withincylindrical body (11402) to thereby rigidize tubular member (11400).Once tubular member (11400) is rigidized, tubular member (11400) mayfunction to provide rigidity to articulation section (11130) and/or toprevent inadvertent deflection of end effector (11040) relative to outersheath (11032).

By way of example only, one or more wires, conductive traces, and/orother electrically conductive conduits may extend along the length ofshaft assembly (11030) to enable electrical power to be selectivelydelivered to magnets (11406). In one merely illustrative example,articulation control assembly (11100) is modified such that knob (11120)causes closure of an electrical switch when knob (11120) is rotated to aneutral position that is associated with articulation section (11130)being in a straight, non-articulated configuration. This switch may bein communication with magnets (11406) and a source of electrical powersuch that magnets (11406) are activated when knob (11120) is in theneutral position. Articulation section (11130) will thus be rigidizedwhen knob (11120) is in the neutral position, with articulation section(11130) in the straight, non-articulated configuration. As soon as knob(11120) is rotated away from the neutral position to articulatearticulation section (11130), the switch will be transitioned to an openstate, thereby deactivating magnets (11406), thereby de-rigidizingarticulation section (11130) and allowing articulation section (11130)to be articulated. When knob (11120) is subsequently rotated back to theneutral position, the switch will again be closed, thereby re-activatingmagnets (11406), thereby rigidizing articulation section (11130) againas articulation section (11130) reaches the straight, non-articulatedconfiguration. Various other suitable ways in which magnets (11406) maybe selectively activated will be apparent to those of ordinary skill inthe art in view of the teachings herein.

L. Exemplary Rigidizing Valve Assembly

FIG. 138 shows a modified version of shaft assembly (11030) ofinstrument (11010) described above having a valve assembly (11420). Aswill be described in more detail below, valve assembly (11420) isconfigured to selectively rigidize so as to provide rigidity toarticulation section (11130) and/or to prevent inadvertent deflection ofend effector (11040) relative to outer sheath (11032). Valve assembly(11420) comprises a pair of plungers (11422, 11424) that are slidablydisposed within a pair of cylinders (11426, 11428). Plungers (11422,11424) are coupled with articulation bands (11140, 11142) of shaftassembly (11130) such that translation of articulation bands (11140,11142) caused by articulation of articulation section (11130) causesconcurrent translation of plungers (11422, 11424) within cylinders(11426, 11428). Cylinders (11426, 11428) are filled with MR fluid(11430, 11432). One or more electromagnets (not shown) are in directcontact with MR fluid (11430, 11432) such that the electromagnets mayselectively magnetize MR fluid (11430, 11432) when the electromagnetsare activated. Prior to magnetizing MR fluid (11430, 11432), plungers(11422, 11424) are operable to translate within cylinders (11426, 11428)to thereby allow articulation section (11130) to flex to thereby deflectend effector (11040) relative to outer sheath (11032). Once MR fluid(11430, 11432) is magnetized, however, MR fluid (110430, 11432) becomessubstantially rigid within cylinders (11426, 11428) to thereby preventmovement of plungers (11422, 11424) to thereby prevent movement ofarticulation bands (11140, 11142) so as to provide rigidity toarticulation section (11130) and/or to prevent inadvertent deflection ofend effector (11040) relative to outer sheath (11032). Various suitableways in which MR fluid (11430, 11432) may be selectively magnetized willbe apparent to those of ordinary skill in the art in view of theteachings herein.

M. Exemplary Stiffening Friction Features

FIG. 139 shows a modified version shaft assembly (11030) of instrument(11010) described above having a pair of exemplary alternativearticulation bands (11440, 11442). As will be described in more detailbelow, articulation bands (11440, 11442) may function to providerigidity to articulation section (11130) and/or to prevent inadvertentdeflection of end effector (11040) relative to outer sheath (11032).Each articulation band (11440, 11442) comprises a plurality of teeth(11444, 11446) projecting outwardly from opposing side surfaces ofarticulation bands (11440, 11442). An interior surface of outer sheath(11032) comprises two sets of teeth (11450, 11452) projecting inwardlyfrom opposing sides of an interior surface of outer sheath (11032).Teeth (11444, 11446) of articulation bands (11440, 11442) are configuredto engage teeth (11450, 11452) of outer sheath (11032) to thereby limitlongitudinal translation of articulation bands (11440, 11442). Limitingthe longitudinal translation of articulation bands (11440, 11442)subsequently limits articulation of articulation section (11130). Thus,it should be understood that depending upon the amount of engagementbetween teeth (11444, 11446) of articulation bands (11440, 11442) andteeth (450, 11452) of outer sheath (32), teeth (444, 11446, 11450,11452) may function to merely limit actuation of articulation section(11130) or to substantially limit actuation of articulation section(11130) by requiring a lesser or greater force to articulatearticulation section (11130).

In some versions, articulation bands (11440, 11442) are configured totransition laterally between an inward configuration and an outwardconfiguration. When articulation bands (11440, 11442) are in the inwardconfiguration, teeth (11444, 11446) are disengaged from teeth (11450,11452), allowing articulation bands (11440, 11442) to translate freely(e.g., to freely drive articulation of articulation section (11130)).When articulation bands (11440, 11442) are in the outward configuration,teeth (11444, 11446) are engaged with teeth (11450, 11452), with enoughforce to prevent articulation bands (11440, 11442) from translating.With articulation bands (11440, 11442) being rigidly prevented fromtranslating, articulation section (11130) is effectively rigidized.Various suitable ways in which articulation bands (11440, 11442) may beselectively transitioned between the inward configuration and theoutward configuration will be apparent to those of ordinary skill in theart in view of the teachings herein.

In some other versions, articulation bands (11440, 11442) areresiliently biased outwardly such that teeth (11444, 11446) are biasedinto engagement with teeth (11450, 11452). Teeth (11444, 11446) remainengaged with teeth (11450, 11452), yet teeth (11444, 11446) arepermitted to slide along teeth (11450, 11452) in a ratcheting fashion asarticulation bands (11440, 11442) are opposingly translated to drivearticulation of articulation section (11130). When articulation bands(11440, 11442) are held longitudinally stationary, engagement betweenteeth (11444, 11446) and teeth (11450, 11452) will prevent articulationsection (11130) from having any “play”, such that teeth (11444, 11446)and teeth (11450, 11452) cooperate to effectively rigidize articulationsection (11130). It should be noted that teeth (11444, 11446) and teeth(11450, 11452) are positioned proximate to articulation section (11130)in this example, thereby minimizing any tolerance stacking that mightotherwise frustrate the rigidization functionality in cases where teeth(11444, 11446) and teeth (11450, 11452) would be positioned furtherremotely from articulation section (11130).

N. Exemplary “Smart Material” Articulation Bands

FIGS. 140A and 140B show a modified version of shaft assembly (11030) ofinstrument (11010) described above having a pair of exemplaryalternative articulation bands (11460, 11462). Articulation bands(11460, 11462) are coupled with a power source (11464) that is operableto provide an electrical current to articulation bands (11460, 11462).Articulation bands (11460, 11462) of the present example comprise a“smart material” (e.g. “muscle wire” shape memory alloy, electroactivepolymer, etc.). In the absence of a current being applied to it, such a“smart material” may be stretched by a small force. Thus, as shown inFIG. 140B, in the absence of a current applied to articulation bands(11460, 11462), articulation bands (11460, 11462) may easily flex tothereby allow articulation section (11130) to flex so as to deflect endeffector (11040) relative to outer sheath (11032). Once a current isapplied to such a “smart material,” the material becomes substantiallyharder and returns to its original length (e.g., a length that isshorter than the length when the current is removed). Thus, as shown inFIG. 140A, once power source (11464) provides an electrical current toarticulation bands (11460, 11462), articulation bands (11460, 11462)become substantially rigid and return to their original (e.g., shorter)lengths so as to provide rigidity to articulation section (11130) and/orto prevent inadvertent deflection of end effector (11040) relative toouter sheath (11032). Various suitable ways in which articulation bands(11460, 11462) may be selectively activated by power source (11464) willbe apparent to those of ordinary skill in the art in view of theteachings herein.

XIII. ULTRASONIC SURGICAL INSTRUMENT WITH RIGIDIZING ARTICULATION DRIVEMEMBERS

As noted above, in some examples it may be desirable to include variousfeatures to selectively increase the rigidity of an articulationsection, such as articulation section (130) described above. Forinstance, because of various factors such as manufacturing tolerances,design limitations, material limitations, and/or other factors,articulation sections of some examples may be susceptible to some “play”or other small movement of the articulation section despite beingrelatively fixed in a given position, such that the articulation sectionis not entirely rigid. It may be desirable to reduce or eliminate suchplay in the articulation section, particularly when the articulationsection is in a straight, non-articulated configuration. In someexamples, such play may be reduced or eliminated by including featuresfor selectively increasing tension in one or two articulation bandssimilar to articulation bands (140, 142) described above. Such featuresmay reduce or eliminate play in the articulation section because theincreased tension in the articulation bands may cause the components ofthe articulation section to longitudinally compress, thereby increasingthe rigidity of the articulation section. It may be desirable to providecontrol of such features via the handle assembly and/or via the shaftassembly because such positioning may provide enhanced usability,ergonomics, and/or functionality.

In some versions, one or more resilient members resiliently biasarticulation bands (140, 142) proximally in order to increase tension inarticulation bands (140, 142). Various suitable ways in which one ormore resilient members may be used to resiliently bias articulationbands (140, 142) proximally will be apparent to those of ordinary skillin the art in view of the teachings herein. Various examples of featuresthat are configured to selectively increase tension in articulationbands are described in greater detail below. In some examples, tensionis selectively increased in one articulation band (140, 142) in order toeffectively ridigize the articulation section. In some other examples,tension is selectively increased in both articulation bands (140, 142)simultaneously in order to effectively ridigize the articulationsection. Various other examples will be apparent to those of ordinaryskill in the art in view of to the teachings herein.

A. Exemplary Alternative Articulation Control Assembly with RigidizingCam Feature

FIGS. 141-144 show an exemplary alternative articulation controlassembly (12200) that may be readily incorporated into instrument (10).Except as otherwise noted herein, it should be understood thatarticulation control assembly (12200) is substantially the same asarticulation control assembly (100) described above. In particular, assimilarly described above, articulation control assembly (12200)comprises a housing (12210) and a rotatable knob (12220). Like withhousing (110) described above, housing (12210) of the present examplecomprises a pair of perpendicularly intersecting cylindrical portions(12212, 12214). Similarly, like knob (120), knob (12220) is rotatablydisposed within a first hollow cylindrical portion (12212) of housing(12210) such that knob (12220) is operable to rotate within cylindricalportion (12212) of housing (12210).

Shaft assembly (30) is similarly slidably and rotatably disposed withina second cylindrical portion (12214). Shaft assembly (30) comprises apair of translatable members (12261, 12262), both of which extendslidably and longitudinally through the proximal portion of outer sheath(32). Translatable members (12261, 12262) are each longitudinallytranslatable within second cylindrical portion (12214) between a distalposition and a proximal position. Like with translatable member (161,162) described above, translatable members (12261, 12262) aremechanically coupled with respective articulation bands (140, 142) suchthat longitudinal translation of translatable member (12261) causeslongitudinal translation of articulation band (140), and such thatlongitudinal translation of translatable member (12262) causeslongitudinal translation of articulation band (142).

Knob (12220) comprises a pair of pins (12222, 12224) extendingdownwardly from a bottom surface of knob (12220). Pins (12222, 12224)extend into second cylindrical portion (12214) of housing (12210) andare rotatably and slidably disposed within a respective pair of channels(12263, 12264) formed in top surfaces of translatable members (12261,12262). However, unlike pins (122, 124), pins (12222, 12224) of thepresent example each include a cam surface (12229) on the proximal sideof each pin (12222, 12224), as best seen in FIGS. 142-144. As will bedescribed in greater detail below, each cam surface (12229) isconfigured to engage channels (12263, 12264) of translatable members(12261, 12262) to selectively drive translatable members (12261, 12262)proximally.

Channels (12263, 12264), like channels (163, 164) described above, arepositioned on opposite sides of an axis of rotation of knob (12220),such that rotation of knob (12220) about that axis causes opposinglongitudinal translation of translatable members (12261, 12262). Forinstance, rotation of knob (12220) in a first direction causes distallongitudinal translation of translatable member (12261) and articulationband (140), while simultaneously causing proximal longitudinaltranslation of translatable member (12262) and articulation band (142).Rotation of knob (12220) in a second direction causes proximallongitudinal translation of translatable member (12261) and articulationband (140), while simultaneously causing distal longitudinal translationof translatable member (12262) and articulation band (142). Thus, itshould be understood that rotation of knob (12220) causes articulationof articulation section (130) as previously described with respect toinstrument (10).

Unlike housing (110) described above, housing (12210) of the presentexample comprises a pair of detent features (12211, 12213) extendinginwardly from an interior surface of first cylindrical portion (12212).Although detent features (12211, 12213) of the present example are shownas ball and spring detents, it should be understood that any othersuitable detent feature may be used. With knob (12220) rotatablydisposed within first cylindrical portion (12212) of housing (12210),detent features (12211, 12213) are configured to permit knob (12220) tobe selectively repositioned such that detent features (12211, 12213) maybe disposed within a pair of first arcuate channels (12221, 12223) or apair of second arcuate channels (12225, 12227) formed in knob (12220).Thus, it should be understood that rotation of knob (12220) will belimited by movement of detent features (12211, 12213) within channels(12221, 12223, 12225, 12227). Detent features (12211, 12213) also retainknob (12220) in housing (12210), while permitting knob (12220) to beselectively positioned between a first vertical position and a secondvertical position within first cylindrical portion (12212) of housing(12210).

Like with first cylindrical portion (112) described above, an interiorsurface of first cylindrical portion (12212) of the present examplefurther comprises a first angular array of teeth (12216) and a secondangular array of teeth (12218) formed in an interior surface of firstcylindrical portion (12212). Rotatable knob (12220) comprises a pair ofoutwardly extending engagement members (12226, 12228) that areconfigured to engage teeth (12216, 12218) of first cylindrical portion(12212) in a detent relationship to thereby selectively lock knob(12220) in a given rotational position. The engagement of engagementmembers (12226, 12228) with teeth (12216, 12218) may be overcome by auser applying sufficient rotational force to knob (12220); but absentsuch force, the engagement will suffice to maintain the straight orarticulated configuration of articulation section (12230). It shouldtherefore be understood that the ability to selectively lock knob(12220) in a particular rotational position will enable an operator toselectively lock articulation section (12230) in a particular deflectedposition relative to the longitudinal axis defined by outer sheath (32).

FIGS. 143 and 144 show an exemplary use of articulation control assembly(12200). As can be seen in FIG. 143, articulation control assembly(12200) may be initially configured such that knob (12220) is in thefirst vertical position. It should be understood that in the presentexample the first position of knob (12220) corresponds to articulationbands (140, 142) being in high tension to thereby increase the rigidityof articulation section (130). In particular, cam surface (12229) ofeach pin (12222, 12224) fully engages a corresponding cam surface(12265) of each channel (12263, 12264) in each translatable member(12261, 12262). Engagement bet between each cam surface (12229, 12265)causes translatable member (12261, 12262) to be driven proximallyrelative to knob (12220) thereby increasing articulation bands (140,142). Such a tension in articulation bands (140, 142) may take up anyslack that might otherwise exist in articulation section (130), therebyincreasing rigidity in articulation section (130) because such tensionplaces articulation section (130) in compression. It should beunderstood that it may be desirable to only move knob (12220) to thevertical position shown in FIG. 143 when articulation section (130) isin a straight, non-articulated configuration.

Detent features (12211, 12213) maintain knob (12220) in the firstposition because detent features (12211, 12213) resiliently engagearcuate channels (12221, 12223) of knob (12220). To articulatearticulation section (130) an operator will first have to decrease therigidity of articulation section (130). When an operator desires todecrease the rigidity of articulation section (130), an operator maytransition knob (12220) to the second vertical position as seen in FIG.144. To transition knob (12220) to the second position, an operator mayapply an upward force to knob (12220) by pulling upwardly on knob(12220) while holding housing (12210) stationary. Such an upward forceshould be sufficient to overcome the resiliency of detent features(12211, 12213) to thereby disengage detent features from arcuatechannels (12221, 12223). Once detent features (12211, 12213) aredisengaged from arcuate channels (12221, 12223) further upward movementof knob (12220) will cause detent features to engage arcuate channels(12225, 12227) to thereby lock knob (12220) in the second verticalposition as shown in FIG. 144.

Once knob (12220) is in the second vertical position, the tension inarticulation bands (140, 142) is released and articulation section (130)is in a configuration for articulation. In particular, as can be seen inFIG. 144, knob (12220) is positioned relative to each translatablemember (12261, 12262) such that cam surface (12229) of each pin (12222,12224) only partially engages the corresponding cam surface (12265)defined by each translatable member (12261, 12262). Such engagement maypermit each translatable member (12261, 12262) to translate distallythereby reducing the tension in articulation bands (140, 142).

When knob (12220) is in the second position, such a positioning may bevisually indicated by an indicator (12219) on knob (12220). In thepresent example, indicator (12219) (as seen in FIG. 142) is shown as ared stripe around the exterior of knob (12220). When knob (12220) is inthe first position, indicator (12219) is covered by cylindrical portion(12212) of housing (12210) and is thereby obscured from view. Yet in thesecond position, indicator (12219) is visible because knob (12220) is ina higher vertical position relative to housing (12210), such thatindicator (12219) is exposed. Although indicator (12219) is shown as ared stripe in the present example, it should be understood in otherexamples, any other color or any other type of indicator may be used.

With rotation knob (12220) in the second position, an operator mayarticulate articulation section (130) by applying a rotational force toknob (12220) to thereby rotate knob (12220). As rotation knob (12220) isrotated, pins (12222, 12224) drive translatable members (12261, 12262)in opposing directions as described above thereby articulatingarticulation section (130). Once articulation section (130) isarticulated to a desired position, an operator may cease rotation ofknob (12220). In some versions, if an operator desires to increase therigidity of articulation section (130) once articulation section (130)is in the desired position, an operator may force knob (12220)downwardly to the first position as described above in order toeffectively ridigize articulation section (130). In some other versions,articulation section (130) may only be rigidized by forcing knob (12220)downwardly to the second vertical position when articulation section(130) is in a straight, non-articulated configuration.

B. Exemplary Alternative Articulation Control Assembly with PivotingRotatable Knob

FIGS. 145-147 show an exemplary alternative articulation controlassembly (12300) that may be readily incorporated into instrument (10).Except as otherwise noted herein, it should be understood thatarticulation control assembly (12300) is substantially the same asarticulation control assembly (100) described above. In particular, assimilarly described above, articulation control assembly (12300)comprises a housing (12310) and a rotatable knob (12320). Like withhousing (110) described above, housing (12310) of the present examplecomprises a pair of perpendicularly intersecting cylindrical portions(12312, 12314). Similarly, like knob (120), knob (12320) is rotatablydisposed within a first hollow cylindrical portion (12312) of housing(12310) such that knob (12320) is operable to rotate within cylindricalportion (12312) of housing (12310).

Shaft assembly (30) is similarly slidably and rotatably disposed withina second cylindrical portion (12314). As can best be seen in FIG. 146,shaft assembly (30) comprises a pair of translatable members (12361)(though only a single translatable member is shown), both of whichextend slidably and longitudinally through the proximal portion of outersheath (32). Translatable members (12361) are each longitudinallytranslatable within second cylindrical portion (12314) between a distalposition and a proximal position. Like with translatable members (161,162) described above, translatable members (12361) are mechanicallycoupled with respective articulation bands (140, 142) such thatlongitudinal translation of translatable member (12361) causeslongitudinal translation of articulation band (140), and such thatlongitudinal translation of the other translatable member (not shown)causes longitudinal translation of articulation band (142).

Knob (12320) comprises a pair of pins (12324) (though only a single pinis shown) extending downwardly from a bottom surface of knob (12320).Pins (12324) extend into second cylindrical portion (12314) of housing(12310) and are rotatably and slidably disposed within a respective pairof channels (12363) (though only a single channel is shown) formed intop surfaces of translatable members (12361). Channels (12363), likechannels (163, 164) described above, are positioned on opposite sides ofan axis of rotation of knob (12320), such that rotation of knob (12320)about that axis causes opposing longitudinal translation of translatablemembers (12361). For instance, rotation of knob (12320) in a firstdirection causes distal longitudinal translation of translatable member(12361) and articulation band (140), while simultaneously causingproximal longitudinal translation of translatable member andarticulation band (142). Rotation of knob (12320) in a second directioncauses proximal longitudinal translation of translatable member (12361)and articulation band (140), while simultaneously causing distallongitudinal translation of translatable member and articulation band(142). Thus, it should be understood that rotation of knob (12320)causes articulation of articulation section (130) a previously describedwith respect to instrument (10).

Unlike housing (110) described above, housing (12310) of the presentexample comprises a single set screw (12313) extending inwardly from aninterior surface of first cylindrical portion (12312). With knob (12320)rotatably disposed within first cylindrical portion (12312) of housing(12310), set screw (12313) is slidably disposed within an arcuatechannel (12323) formed in knob (12320). Thus, it should be understoodthat rotation of knob (12320) will be limited by movement of set screws(12313) within channel (12323). Set screw (12313) also retain knob(12320) in housing (12310), preventing knob (12320) from travelingvertically within first cylindrical portion (12312) of housing (12310).

Housing (12310) further includes an open portion (12311). As can best beseen in FIG. 145, open portion (12311) is disposed on the distal face ofhousing (12310) and is formed as a vertically extending channel thatinterrupts the circumference of cylindrical portion (12312). Generally,open portion (12311) is configured to permit at least a portion of knob(12320) to pass distally through housing (12310). As will be describedin greater detail below, open portion (12311) is configured to permitpassage of at least a portion of knob (12320) because such a featurepermits at least a portion of knob (12320) to be pivotable relative tohousing (12310). A knob lock (12315) is disposed adjacent to openportion (12311). Knob lock (12315) is configured to selectively lock andunlock pivoting of knob (12320) by selectively closing at least aportion of open portion (12311) or otherwise engaging knob (12320) toprevent pivoting. By way of example only, knob lock (12315) may comprisea “C” shaped member that selectively rotates about cylindrical portion(12312) to selectively close off or open the open portion (12311) ofcylindrical portion (12312). As another merely illustrative example,knob lock (12315) may comprise a protrusion that selectively extendsinto or over a portion of open portion (12311). Various suitable ways inwhich a knob lock (12315) may be configured and operable will beapparent to those of ordinary skill in the art in view of the teachingsherein.

Like with first cylindrical portion (112) described above, an interiorsurface of first cylindrical portion (12312) of the present examplecomprises a first angular array of teeth (not shown) and a secondangular array of teeth (not shown) formed in an interior surface offirst cylindrical portion (12312). Likewise, knob (12320) comprises apair of outwardly extending engagement members (not shown) that areconfigured to engage the teeth of first cylindrical portion (12312) in adetent relationship to thereby selectively lock knob (12320) in a givenrotational position. The engagement of the engagement members with theteeth may be overcome by a user applying sufficient rotational force toknob (12320); but absent such force, the engagement will suffice tomaintain the straight or articulated configuration of articulationsection (12330). It should therefore be understood that the ability toselectively lock knob (12320) in a particular rotational position lockwill enable an operator to selectively lock articulation section (12330)in a particular deflected position relative to the longitudinal axisdefined by outer sheath (32).

FIGS. 146 and 147 show an exemplary use of articulation control assembly(12300) to selectively stiffen articulation section (130). It should beunderstood that in some examples it may be desirable to pivotarticulation control assembly (12300) to selectively stiffenarticulation section (130) because such a feature may improve usabilityand/or ergonomics. As can be seen in FIG. 146, articulation controlassembly (12300) may be initially configured such that knob (12320) isin a first pivotal position. It should be understood that in the presentexample the first pivotal position of knob (12320) corresponds toarticulation bands (140, 142) being relatively relaxed to such thatarticulation bands (140, 142) are in a configuration for articulatingarticulation section (130). Further, the first pivotal positioncorresponds to knob (12320) being seated within first cylindricalportion (12312) of housing (12310). Thus, knob (12320) is positioned torotate within first cylindrical position (12312) about a rotation axisto opposingly drive translatable members (12361) via pins (12324).Accordingly, an operator may rotate knob (12320) about the rotation axiswhile knob (12320) is in the first pivotal position in order toarticulate articulation section (130). Additionally, to maintain knob(12320) within first cylindrical portion (12312) while the articulationfeature is in use, an operator may optionally engage knob lock (12315)in a locked position.

Once an operator desires to increase the rigidity of articulationsection (130), an operator may first transition knob lock (12315) to anunlocked position to thereby permit pivotal motion of knob (12320) abouta pivot axis. In this example, the pivot axis is perpendicular to therotation axis of knob (12320) and offset from the rotation axis of knob(12320). The pivot axis is also perpendicular to the longitudinal axisof shaft assembly (30) and offset from the longitudinal axis of shaftassembly (30). In particular, in the views shown in FIGS. 146-147, thepivot axis runs into and out of the page, the rotation axis runsvertically between the top of the view and the bottom of the view, andthe longitudinal axis runs horizontally between the sides of the view.Once knob lock (12315) is in the unlocked position, at least a portionof knob (12320) is permitted to pass through open portion (12311) ofhousing (12310). To increase the rigidity of articulation section (130)an operator may next apply a horizontal force to knob (12320) (e.g., tothe left-hand side of the view shown in FIGS. 146-147) while holdinghousing (12310) stationary. Such a horizontal force acting on knob(12320) may begin to pivot knob (12320) about the pivot axis toward theposition shown in FIG. 147.

The above described pivoting of knob (12320) may be provided and carriedout in numerous different ways. For instance, in some examples knob(12320) is comprised of three separate components—a pivoting member, andtwo side members. In such an example, the pivoting member is be securedto each of the side members by a shaft suitable for pivoting thepivoting member relative to the two side members. In other examples,first cylindrical portion (12312) may be equipped with a hinge member orother feature that may be equipped to permit both knob (12320) and firstcylindrical portion (12312) to pivot relative to second cylindricalportion (12314). Alternative, any other suitable mechanism for pivotingknob (12320) may be used as will be apparent to those of ordinary skillin the art in view of the teachings herein.

Regardless of the particular mechanism for pivoting knob (12320), itshould be understood that as knob (12320) is pivoted, the pivotingaction generally applies tension to articulation bands (140, 142) viapins (12324) and translatable members (12361), thereby increasing therigidity of articulation section (130). In particular, the pivoting ofknob (12320) causes pins (12324) to move about the pivot axis. As pins(12324) move, pins (12324) engage a proximal portion of eachtranslatable member (12361) such that further movement of pins (12324)will simultaneously drive each translatable member (12361) proximally.As translatable members (12361) are driven proximally, tension iscommunicated to articulation bands (140, 142) to increase the rigidityof articulation section (130) by taking up any slack that mightotherwise exist in articulation section (130). It should be understoodthat, in the present example, knob (12320) may be pivoted to theposition shown in FIG. 147 only when articulation section (130) is in astraight, non-articulated configuration. Some other versions may permitknob (12320) to be pivoted to the position shown in FIG. 147 whenarticulation section (130) is in an articulated configuration.

With knob (12320) pivoted to a fully pivoted position shown in FIG. 147,articulation bands (140, 142) are in a tensioned configuration andarticulation section (130) is correspondingly in a rigid configuration.Once knob (12320) is pivoted to the fully pivoted position, an operatormay optionally lock knob (12320) in the fully pivoted position bytransitioning knob lock (12315) back to the locked position. However,unlike the locking configuration described above, in this configurationknob lock (12315) engages at least a portion of knob (12320) to maintainknob (12320) in the fully pivoted position. It should be understood thatin some examples, knob (12320) comprises openings, indentations, orother features that receive a portion of knob lock (12314), therebypermitting knob lock (12315) to engage knob (12320).

C. Exemplary Alternative Articulation Section with AsymmetricalRetention Collars

FIGS. 148 and 149 show an exemplary alternative articulation sectionthat may be readily incorporated into instrument (10). It should beunderstood that unless otherwise described herein, articulation section(12430) is substantially the same as articulation section (130)described above. For instance, like articulation section (130),articulation section (12430) comprises a pair of ribbed body portions(12432, 12434) surrounding flexible portion (166) of waveguide (180).Similarly, ribbed body portions (12432, 12434) are configured to flexwith flexible portion (12466) of waveguide (180) when articulationsection (12430) bends to achieve an articulated state.

Also like articulation section (130), articulation section (12430)includes a plurality of retention collars (12433). Although retentioncollars (12433) of the present example are configured to surround ribbedbody portions (12432, 12434) and are configured to retain articulationbands (140, 142), retention collars (12433) are also generallyconfigured for the purpose of providing rigidity to articulation section(12430). As can best be seen in FIG. 148, retention collars (12433) ofthe present example are generally wider compared to retention collars(133). With such a width, it should be understood that retention collars(12433) substantially abut each other. Each retention collar (12433) isasymmetrical and comprises an articulating portion (12435) and a lockingportion (12437). Each articulating portion (12435) comprises a chamferededge (12436) on each side of each articulating portion (12435). As willbe described in greater detail below, each chamfered edge (12436) isgenerally at an oblique angle suitable to permit articulation ofarticulation section (12430). In some examples, each chamfered edge(12436) is at an angle of about 15° relative to the longitudinal axis ofeach retention collar (12433), although any other suitable angle may beused.

Each locking portion (12437) is generally square or rectangular inshape. Accordingly, each locking portion (12437) forms a generallystraight edge (12438) positioned adjacent to each chamfered edge (12436)of each articulating portion (12435). As will be understood, eachstraight edge (12438) is generally configured to maintain rigidity ofarticulation section (12430) in a given direction when each retentioncollar (12433) is adjacent to the others.

FIGS. 148 and 149 show an exemplary operation of articulation section(12430). As can be seen in FIG. 148, articulation section (12430) isgenerally both unidirectionally rigid and unidirectionally articulable.For instance, if a transversely oriented force is applied to the distalportion of shaft assembly (30) in the direction of locking portions(12437) and perpendicular to the longitudinal axis of shaft assembly(30), articulation section (12430) resists articulation because eachstraight edge (12438) of each locking portion (12437) that is adjacentto another straight edge (12438) engages with the other straight edge(12438) and thus prevents lateral bending of articulation section(12430). Yet, if a transversely oriented force is applied to the distalportion of shaft assembly (12300) in the direction of articulatingportions (12435) and perpendicular to the longitudinal axis of shaftassembly (30), articulation section (12430) may be articulated becausechamfered edges (12436) of each articulating portion (12435) providesufficient clearance to permit lateral bending of articulation section(12430).

Although articulating portions (12435) permit articulation, it should beunderstood that articulating portions (12435) only permit articulationto the extent that chamfered edges (12436) remain away from each other.Once articulation section (12430) is articulated to a point where eachchamfered edge (12436) is adjacent to another, each chamfered edge(12436) will act as a physical stop to further articulation similarly tostraight edges (12438) of each locking portion (12437). Thus, bothchamfered edges (12436) and straight edges (12438) act as physical stopsthat prevent articulation of articulation section (12430), but straightedges (12438) permit very little to no articulation, while chamferededges (12436) permit a certain predetermined range of articulation.Therefore, if articulation bands (140, 142) are neither in tension norcompression, an operator may apply an articulation force to articulatearticulation section (12430) in only a single direction and only to acertain predetermined extent. By way of example only, chamfered edges(12436) may permit articulation section (12430) to achieve anarticulation angle of up to approximately 30°. Alternatively, any othersuitable maximum articulation angle may be provided. It should beunderstood that the “articulation angle” may be an angle defined betweenthe longitudinal axis of distal outer sheath (33) and the longitudinalaxis of proximal outer sheath (32).

When an operator desires to lock articulation section (12430) in astraight configuration as seen in FIG. 148, a user may place at leastarticulation band (141) in tension thereby compressing retention collars(12433) such that straight edges (12438) of locking portions (12437) arecompressed against each other. While straight edges (12438) will preventarticulation in the direction of locking portions (12437), tension inarticulation band (141) will also prevent articulation in the directiontoward articulating portions (12435). This is because the tension inarticulation band (140) will prevent straight edges (12438) fromseparating relative to each other.

Tension may be applied to articulation band (140) using the articulationcontrol assemblies (110, 12210, 12310) described above, or any othersuitable means. Articulation band (142) may also be placed in tensionusing the features of articulation assemblies (12210, 12310) describedabove, or any other suitable means. Alternatively, articulation band(142) may merely be passive in state with merely no force applied.

When an operator desires to articulate articulation section (12430), anoperator may release tension from articulation band (140). Once tensionis released from articulation band (140), articulation section (12430)will be in the passive state described above where articulation ispermitted in the direction of articulating portions (12435) but not inthe direction of locking portions (12437). To initiate articulation, anoperator may place articulation band (142) in tension while maintainingarticulation band (140) in a passive state or actively drivingarticulation band (140) distally. Tension may be applied to articulationband (140) using articulation control assemblies (110, 12210, 12310) asdescribed above, or by using any other suitable means. As tension isapplied, articulation band (142) generates a moment that bendsarticulation section (12430). Articulation section (12430) is thenpermitted to bend until chamfered edges (12436) of articulating portions(12435) are adjacent to each other. At such a point chamfered edges(12436) begin acting as physical stops as described above therebypreventing further articulation.

FIG. 150 shows an exemplary alternative housing (12510) that may bereadily incorporated into instrument (10), particularly when instrument(10) is equipped with articulation section (12430) described above.Unless otherwise described herein, it should be understood that housing(12510) is substantially the same as housing (110) described above.Additionally, it should be understood that any of the features describedherein with respect to housing (12510) may be readily incorporated intoany housings (110, 12210, 12310) described above.

Like with housing (110), housing (12510) comprises a first cylindricalportion (12512) and a second cylindrical portion (12514). Secondcylindrical portion (12514) is substantially the same as secondcylindrical portion (114) described above such that further details willnot be described herein.

First cylindrical portion (12512) is substantially the same as firstcylindrical portion (112) described above. For instance, as can be seenin FIG. 150, first cylindrical portion (12512) comprises a first angulararray of teeth (12516) and a second angular array of teeth (12518)formed in an interior surface of first cylindrical portion (12512).However, unlike teeth (116, 118) described above, teeth (12516, 12518)of the present example are configured for use with articulation section(12430) described above. In particular, each angular array of teeth(12516, 12518) comprises a respective plurality of articulation teeth(12520, 12522), a single lock tooth valley (12524, 12526), and anexaggerated tooth (12528, 12529) separating the articulation teeth(12520, 12522) from the lock tooth valley (12524, 12526).

Each set of articulation teeth (12520, 12522) functions similarly toteeth (116, 118) described above. For instance, articulation teeth(12520, 12522) are configured to engage engagement members (126, 128) ofrotatable knob (120) such that knob (120) may be rotated to articulatearticulation section (12430) to a desired position and remain in thesame position once any rotational force is removed from knob (120).However, unlike teeth (116, 118), articulation teeth (12520, 12522) aredisposed for movement of articulation section (12430) in only a singledirection because, as described above, articulation section (12430) isonly configured for articulation in a single direction.

Each lock tooth valley (12524, 12526) is configured to hold knob (120)in a position corresponding to a locked position of articulation section(12430). It should be understood that each lock tooth valley (12524,12526) is disposed in a position corresponding to knob (120) beingrotated slightly past a neutral position (e.g., the position alignedwith the longitudinal axis of instrument (10)). This positioning ensuresthat some tension will be applied to actuation band (140) to achieve thelocking configuration described above with respect to articulationsection (12430) while articulation section (12430) is in a substantiallystraight, non-articulated configuration. Although each lock tooth valley(12524, 12526) of the present example is shown in a given position, itshould be understood that the precise position of each lock tooth valley(12524, 12526) may be varied as desired to achieve a sufficient level oftension in actuation band (140).

Each exaggerated tooth (12528, 12529) is positioned between each set ofactuation teeth (12520, 12522) and each lock tooth valley (12524,12526). Each exaggerated tooth (12528, 12529) is configured to act as adetent feature that may provide additional support to hold knob (120) inthe locked position described above. In particular, each exaggeratedtooth (12528, 12529) is configured to engage engagement members (126,128) to hold engagement members (126, 128) respective lock tooth valleys(12524, 12526). Additionally, each exaggerated tooth (12528, 12529) mayact to provide tactile feedback to an operator as knob (120) istransitioned between each set of actuation teeth (12520, 12522) and eachlock tooth valley (12524, 12526). Although each exaggerated tooth(12528, 12529) of the present example is shown as having a particularsize, it should be understood that the configuration of exaggeratedtooth (12528, 12529) may be varied as desired to achieve suitable detentand/or tactile feedback characteristics.

D. Exemplary Alternative Articulation Section with Articulation Segments

FIG. 151 shows another exemplary alternative articulation section(12630) that may be readily incorporated into instrument (10).Articulation section (12630) comprises three articulation segments(12632, 12642, 12652) disposed between a distal block (12660) and aproximal block (12664). Articulation segments (12632, 12642, 12652) areconfigured to operate cooperatively to act as physical stops fordifferent amounts of articulation for a given side of each articulationsegment (12632, 12642, 12652). Articulation segments (12632, 12642,12652) consist of a first articulation segment (12632), a secondarticulation segment (12642), and a third articulation segment (12652).Although three total articulation segments are shown, it should beunderstood that in other examples, any suitable number of articulationsegments (12632, 12642, 12652) may be used. For instance, in someexamples a plurality of second articulation segments (12642) may beincorporated between first and third articulation segments (12632,12652). In still other examples, second articulation segment (12642) maybe omitted altogether with first and third articulation segments (12632,12652) being adjacent to each other.

First articulation segment (12632) includes an articulation portion(12633) and a lock portion (12636). Articulation portion (12633)comprises a straight end (12634) disposed adjacent to distal block(12660) and a chamfered end (12635) disposed adjacent to secondarticulation segment (12642). Straight end (12634) is generally straightand is configured to rest squarely against distal block (12660).Chamfered end (12635) is configured with a chamfer disposed at an angleof approximately 15° relative to the longitudinal axis of firstarticulation segment (12632). As will be described in greater detailbelow, chamfered end (12635) is generally configured to permitarticulation of articulation section (12630) for a certain amount ofarticulation (e.g., approximately 30°) before acting as a physical stop.

Lock portion (12636) comprises a straight end (12637) and a chamferedend (12638). Straight end (12637) is generally straight and isconfigured to rest squarely against distal block (12660). Chamfered end(12638) is configured with a chamfer disposed at an angle ofapproximately 1° to 5° relative to the longitudinal axis of firstarticulation segment (12632). While chamfered end (12638) is configuredto permit some articulation of articulation section (12630), it shouldbe understood that chamfered end (12638) is configured to permit only alimited amount of articulation prior to acting as a physical stop. Thisis because of the relatively shallow chamfer angle as compared to thechamfer angle of chamfered end (12635) described above. Accordingly, aswill be described in greater detail below, lock portion (12636)generally acts a physical stop for articulation in articulation section(12630) despite allowing some relatively limited amount of articulation.

Second articulation segment (12642) includes an articulation portion(12643) and a lock portion (12646). Articulation portion (12643)comprises two chamfered ends (12644, 12645) with a distal chamfered end(12644) disposed adjacent to first articulation segment (12632) and aproximal chamfered end (12645) disposed adjacent to third articulationsegment (12652). Chamfered ends (12644, 12645) are generally symmetricaland are both configured with a chamfer disposed at an angle ofapproximately 15° relative to the longitudinal axis of secondarticulation segment (12642). As will be described in greater detailbelow, chamfered ends (12644, 12645) are generally configured to permitarticulation of articulation section (12630) for a certain amount ofarticulation (e.g., approximately 30°) before acting as a physical stop.

Lock portion (12646) comprises two chamfered ends (12647, 12648) with adistal chamfered end (12647) disposed adjacent to first articulationsegment (12632) and a proximal chamfered end (12648) disposed adjacentto third articulation segment (12652). Chamfered ends (12637, 12638) areboth configured with a chamfer disposed at an angle of approximately 1°to 5° relative to the longitudinal axis of second articulation segment(12642). While chamfered ends (12647, 12648) are configured to permitsome articulation of articulation section (12630), it should beunderstood that chamfered ends (12647, 12648) are configured to permitonly a limited amount of articulation prior to acting as a physicalstop. This is because of the relatively shallow chamfer angle ascompared to the chamfer angle of chamfered ends (12644, 12645) describedabove. Accordingly, as will be described in greater detail below, lockportion (12646) generally acts a physical stop for articulation inarticulation section (12630) despite allowing some relatively limitedamount of articulation.

Third articulation segment (12652) is similar to first articulationsegment (12632) and includes an articulation portion (12653) and a lockportion (12656). Articulation portion (12653) comprises a chamfered end(12654) disposed adjacent to second articulation segment (12642) and astraight end (12655) disposed adjacent to proximal block (12664).Chamfered end (12654) is configured with a chamfer disposed at an angleof approximately 15° relative to the longitudinal axis of thirdarticulation segment (12652). As will be described in greater detailbelow, chamfered end (12654) is generally configured to permitarticulation of articulation section (12630) for a certain amount ofarticulation (e.g., approximately 30°) before acting as a physical stop.Straight end (12655) is generally straight and is configured to restsquarely against proximal block (12664).

Lock portion (12656) comprises a chamfered end (12657) and a straightend (12658). Chamfered end (12657) is configured with a chamfer disposedat an angle of approximately 1° to 5° relative to the longitudinal axisof third articulation segment (12652). While chamfered end (12657) isconfigured to permit some articulation of articulation section (12630),it should be understood that chamfered end (12657) is configured topermit only a limited amount of articulation prior to acting as aphysical stop. This is because of the relatively shallow chamfer angleas compared to the chamfer angle of chamfered end (12654) describedabove. Accordingly, as will be described in greater detail below, lockportion (12656) generally acts a physical stop for articulation inarticulation section (12630) despite allowing some relatively limitedamount of articulation. Straight end (12658) is generally straight andis configured to rest squarely against proximal block (12664).

Each articulation segment (12632, 12642, 12652) includes a respectivebore (12639, 12649, 12659) extending transversely therethough. Each bore(12639, 12649, 12659) is configured to surround but not contactwaveguide (180). For instance, each bore (12639, 12649, 12659) is cutinto a larger portion of each respective lock portion (12636, 12646,12656) relative to each respective articulation portion (12633, 12643,12653). Because each articulation portion (12633, 12643, 12653) isconfigured to articulate articulation section (12630) a larger amountrelative to each lock portion (12636, 12646, 12656), each bore (12639,12649, 12659) is configured to include additional space on the side ofeach lock portion (12636, 12646, 12656) to accommodate bending ofwaveguide (180).

Distal and proximal block (12660, 12664) each similarly include arespective bore (12662, 12666) that is configured to surround waveguide(180) without contacting waveguide (180). Additionally, blocks (12660,12664) are configured to abut articulation segments (12632, 12642,12652) and to provide a stable point of contact for segments (12632,12642, 12652). Although not shown, it should be understood that blocks(12660, 12664) may also include channels or other features configured toprovide a surface for articulation bands (140, 142) to move upon.

In an exemplary mode of operation, an operator may lock articulationsection (12630) in a generally straight configuration by applyingtension to articulation band (140). In particular, tension may beapplied using articulation control assemblies (100, 12200, 12300) asdescribed above. Once tension begins to be applied to articulation band(140), a moment will be created by such tension that will urge chamferedends (12638, 12647) of first and second articulation segments (12632,12642) toward each other and chamfered ends (12648, 12657) of second andthird articulation segments (12642, 12652) toward each other until eachchamfered end (12638, 12647, 12648, 12657) abuts another. Because of thelimited chamfer of chamfered ends (12638, 12647, 12648, 12657) anyarticulation of articulation section (12630) will be limited at thisstage.

Once chamfered ends (12638, 12647, 12648, 12657) are abutting,additional articulation will be prevented by physical contact betweenchamfered ends (12638, 12647, 12648, 12657). Thus, while tension isapplied to articulation band (140), articulation section (130) will beheld in a position of limited to no articulation. It should beunderstood that the particular amount of articulation of articulationsection (630) will be determined by the particular chamfer angles ofchamfered ends (12638, 12647, 12648, 12657).

When an operator desires to articulate articulation section (12630), anoperator may first release any tension in articulation band (140). Oncetension is released, an operator may apply tension to articulation band(142) using articulation control assembly (100, 12200, 12300) describedabove. One tension is applied to articulation band (142), a moment willbe created by such tension that will urge chamfered ends (12635, 12644)of first and second articulation segments (12632, 12642) toward eachother and chamfered ends (12645, 12654) of second and third articulationsegments (12642, 12652) toward each other until each chamfered end(12635, 12644, 12645, 12654) abut another. It should be understood thatbecause of the relatively large chamfer of chamfered ends (12635, 12644,12645, 12654) (compared to chamfered ends (12638, 12647, 12648, 12657)),articulation of articulation section (12630) about articulation portions(12633, 12643, 12653) will be relatively large in comparison toarticulation about lock portions (12636, 12646, 12656). In someexamples, such an articulation of articulation section will beapproximately 30°.

Once chamfered ends (12635, 12644, 12645, 12654) are abutting,additional articulation will be prevented by physical contact betweenchamfered ends (12635, 12644, 12645, 12654). Thus, while tension isapplied to articulation band (140), articulation section (130) will beheld in an articulated position. It should be understood that theparticular amount of articulation of articulation section (12630) willbe determined by the particular chamfer angles of chamfered ends (12635,12644, 12645, 12654). Accordingly, chamfered ends (12635, 12644, 12645,12654) may be configured to permit any suitable amount of articulationas may be desired.

In one merely illustrative example, a modified version of instrument(10) includes articulation section (12630) and housing (12510). Itshould therefore be understood that articulation section (12630) may beoperated in a manner similar to that described above with respect toarticulation section (12430). Alternatively, any other suitable controlelements may be combined with articulation section (12630).

E Exemplary Alternative Instrument with Tensioning Lever

FIG. 152 shows an exemplary alternative instrument (121010). It shouldbe understood that instrument (121010) of the present example issubstantially the same as instrument (10) described above, except asotherwise noted herein. For instance, Instrument (121010) of the presentexample comprises a handle assembly (121020), a shaft assembly (121030),and an end effector (121040). Handle assembly (121020) comprises a body(121022) including a pistol grip (121024) and a pair of buttons(121026). Handle assembly (121020) also includes a trigger (121028) thatis pivotable toward and away from pistol grip (121024). It should beunderstood, however, that various other suitable configurations may beused, including but not limited to a scissor grip configuration. Endeffector (121040) includes an ultrasonic blade (121160) and a pivotingclamp arm (121044). Clamp arm (121044) is coupled with trigger (121028)such that clamp arm (121044) is pivotable toward ultrasonic blade(121160) in response to pivoting of trigger (121028) toward pistol grip(121024); and such that clamp arm (121044) is pivotable away fromultrasonic blade (121160) in response to pivoting of trigger (121028)away from pistol grip (121024). Various suitable ways in which clamp arm(121044) may be coupled with trigger (121028) will be apparent to thoseof ordinary skill in the art in view of the teachings herein. In someversions, one or more resilient members are used to bias clamp arm(121044) and/or trigger (121028) to the open position shown in FIG. 152.

An ultrasonic transducer assembly (121012) extends proximally from body(121022) of handle assembly (121020). Transducer assembly (121012) iscoupled with a generator (121016) via a cable (121014), such thattransducer assembly (121012) receives electrical power from generator(121016). Piezoelectric elements in transducer assembly (121012) convertthat electrical power into ultrasonic vibrations. Generator (121016) mayinclude a power source and control module that is configured to providea power profile to transducer assembly (121012) that is particularlysuited for the generation of ultrasonic vibrations through transducerassembly (121012).

Blade (121160) of the present example is operable to vibrate atultrasonic frequencies in order to effectively cut through and sealtissue. Blade (121160) is positioned at the distal end of an acousticdrivetrain. This acoustic drivetrain includes transducer assembly(121012) and an acoustic waveguide (not shown). The acoustic waveguidecomprises a flexible portion (not shown) similar to flexible portion(166) described above with respect to instrument (10). Transducerassembly (121012) includes a set of piezoelectric discs (not shown)located proximal to a horn (not shown) of the waveguide. Thepiezoelectric discs are operable to convert electrical power intoultrasonic vibrations, which are then transmitted along the waveguide toblade (121160) in accordance with known configurations and techniques.By way of example only, this portion of the acoustic drivetrain may beconfigured in accordance with various teachings of various referencesthat are cited herein.

Shaft assembly (121030) of the present example extends distally fromhandle assembly (121020). Unless otherwise noted herein, shaft assembly(121030) is substantially the same as shaft assembly (30) describedabove with respect to instrument. For instance, shaft assembly (121030)includes an articulation section (121130), which is located at a distalportion of shaft assembly (121030), with end effector (121040) beinglocated distal to articulation section (121130). As shown in FIG. 152, aknob (121031) is secured to a proximal portion of shaft assembly(121030). Knob (121031) is rotatable relative to body (121022), suchthat shaft assembly (121030) is rotatable about the longitudinal axisdefined by shaft assembly (121030), relative to handle assembly(121020). Such rotation may provide rotation of end effector (121040),articulation section (121130), and shaft assembly (121030) unitarily. Ofcourse, rotatable features may simply be omitted if desired.

Articulation section (121130) is substantially the same as articulationsection (130) described above with respect to instrument (10), unlessotherwise note herein. For instance, articulation section (121130) isoperable to selectively position end effector (121040) at variouslateral deflection angles relative to a longitudinal axis defined byshaft assembly (121030). Like with articulation section (130),articulation section (121130) is driven by a pair of articulation bands(121140, 121142) disposed within articulation section (121130) andextending through shaft assembly (121030). When articulation bands(121140, 121142) translate longitudinally in an opposing fashion, thiswill cause articulation section (121130) to bend, thereby laterallydeflecting end effector (121040) away from the longitudinal axis ofshaft assembly (121030) from a straight configuration to an articulatedconfiguration. In particular, end effector (121040) will be articulatedtoward the articulation band (121140, 121142) that is being pulledproximally. During such articulation, the other articulation band(121140, 121142) may be pulled or pushed distally

Instrument further includes an articulation control assembly (121100)that is secured to a proximal portion of shaft assembly (121030).Articulation control assembly (121100) comprises a housing (121110) anda rotatable knob (121120). Like with articulation control assembly (100)described above, rotatable knob (121120) is configured to rotaterelative to housing (121110) to drive articulation bands (121140,121142) in opposing longitudinal directions. For instance, rotation ofknob (121120) in a first direction causes distal longitudinaltranslation of articulation band (121140), while simultaneously causingproximal longitudinal translation of articulation band (121142).Rotation of knob (121120) in a second direction causes proximallongitudinal translation of articulation band (121140), whilesimultaneously causing distal longitudinal translation of articulationband (121142). Thus, it should be understood that rotation of rotationknob (121120) causes articulation of articulation section (121130).

Unlike instrument (10) described above, instrument (121010) of thepresent example further includes a tensioning assembly (121200).Tensioning assembly (121200) is generally operable to translate theentire articulation control assembly (121100) relative to shaft assembly(121030) to thereby simultaneously apply tension to articulation bands(121140, 121142). As can best be seen in FIG. 153, tensioning assembly(121200) comprises a lever arm (121210) and a link (121220). Lever arm(121210) is pivotably secured within handle assembly (121020) and isconfigured to pivot about a pivot point (121212) connecting lever arm(121210) to housing (121020).

Link (121220) is pivotably connected to lever arm (121210) at a pivotpoint (121222) connecting link (121220) to lever arm (121210). Link(121220) extends from lever arm (121210) through handle assembly(121020) and through knob (121031) where link (121220) pivotablyconnects to articulation control assembly (121100). Although not shown,it should be understood that link (121220) may connect to articulationcontrol assembly (121100) by any suitable means. For instance, in someexamples link (121220) is connected to articulation control assembly(121100) by a rotatable collar assembly that is configured to permitarticulation control assembly (121100) to rotate relative to link(121220) while still permitting link (121220) to drive translation ofarticulation control assembly (121100). In other examples, link (121220)may simply be integral with articulation control assembly (121100) orconnected with a pin or other securing feature. Of course any othersuitable mechanisms for connecting link (121220) to articulation controlassembly (121100) as will be apparent to those of ordinary skill in theart in view of the teachings herein.

As can best be seen in FIG. 154, articulation control assembly (121100)is configured to translate relative to knob (121031) and shaft assembly(121030). In particular, a proximal portion of housing (121110) istranslatably received within knob (121031) to permit some translation ofarticulation control assembly (121100) relative to knob (121031).Additionally, a spring (121224) is disposed between articulation controlassembly (121100) and knob (121031) to resiliently bias articulationcontrol assembly (121100) toward a distal position. As will be describedin greater detail below, the distal position of articulation controlassembly (121100) corresponds to an articulation position, wherearticulation bands (121140, 121142) are subjected to low tension, suchthat articulation control assembly (121100) may cause articulationsection (121130) to articulate.

FIGS. 153 and 155 show an exemplary mode of operation of tensioningassembly (1200). In particular, FIG. 153 shows tensioning assembly(121200) in an articulation position. Generally, the articulationposition corresponds to articulation bands (121140, 121142) being in alow tension state such that knob (121120) of articulation controlassembly (121100) may be used to drive articulation bands (121140,121142) in opposing directions to articulate articulation section(121130). In the articulation position, lever arm (121210) is pivoteddistally relative to handle assembly (121020). Because link (121220) isattached to lever arm (121210), link (121220) is also positioneddistally to thereby permit spring (121224) to drive articulation controlassembly (121100) distally.

An operator may desire to increase the rigidity of articulation section(121130) to thereby lock articulation section (121130) in a particularstate of articulation (e.g., straight). To do so, it may be desirable tosimultaneously apply tension to both articulation bands (121140, 121142)because such tension may provide opposing forces on articulation section(121130) that work to maintain articulation section (121130) in a givenposition. To simultaneously tension both articulation bands (121140,121142), an operator may grasp lever arm (121210) and pull lever arm(121210) proximally relative to handle assembly (121020).

As can be seen in FIG. 155, pulling lever arm (121210) proximally causeslink (121220) to act on articulation control assembly (121100) tothereby translate articulation control assembly (121100) proximallyrelative to knob (121031). Because articulation bands (121140, 121142)are both connected to articulation control assembly (121100), suchtranslation will simultaneously increase tension each articulation band(121140, 121142). This tension will be transferred to the movablecomponents within articulation section (121130), thereby taking up anyslack that might otherwise exist within articulation section (121130).Once tension is applied to articulation bands (121140, 121142), theparticular articulation state of articulation section (121130) (e.g.,straight) will thus correspondingly be locked.

In some examples, tensioning assembly (121200) may include a lockfeature or other mechanism to selectively maintain lever arm (121210) inthe tensioned position. Where such features are included, an operatormay actuate such features after lever arm (121210) is positioned totension articulation bands (121140, 121142). As another merelyillustrative example, lever arm (121210) and link (121220) may beconfigured to provide an over-center toggle mechanism, such as theover-center toggle described below. Alternatively, locking features maybe omitted and lever arm (121210) may simply return to the articulationposition once an operator releases lever arm (121210), due to theresilience of spring (121224).

F. Exemplary Alternative Instrument with Over-Center Toggle TensioningAssembly

FIG. 156 shows an exemplary alternative instrument (121310). It shouldbe understood that instrument (121310) of the present example issubstantially the same as instrument (10) described above, except asotherwise noted herein. For instance, Instrument (121310) of the presentexample comprises a handle assembly (121320), a shaft assembly (121330),and an end effector (121340). Handle assembly (121320) comprises a body(121322) including a pistol grip (121324) and a pair of buttons(121326). Handle assembly (121320) also includes a trigger (121328) thatis pivotable toward and away from pistol grip (121324). It should beunderstood, however, that various other suitable configurations may beused, including but not limited to a scissor grip configuration. Endeffector (121340) includes an ultrasonic blade (121460) and a pivotingclamp arm (121344). Clamp arm (121344) is coupled with trigger (121328)such that clamp arm (121344) is pivotable toward ultrasonic blade(121460) in response to pivoting of trigger (121328) toward pistol grip(121324); and such that clamp arm (121344) is pivotable away fromultrasonic blade (121460) in response to pivoting of trigger (121328)away from pistol grip (121324). Various suitable ways in which clamp arm(121344) may be coupled with trigger (121328) will be apparent to thoseof ordinary skill in the art in view of the teachings herein. In someversions, one or more resilient members are used to bias clamp arm(121344) and/or trigger (121328) to the open position shown in FIG. 156.

An ultrasonic transducer assembly (121312) extends proximally from body(121322) of handle assembly (121320). Transducer assembly (121312) iscoupled with a generator (121316) via a cable (121314), such thattransducer assembly (121312) receives electrical power from generator(121316). Piezoelectric elements in transducer assembly (121312) convertthat electrical power into ultrasonic vibrations. Generator (121316) mayinclude a power source and control module that is configured to providea power profile to transducer assembly (121312) that is particularlysuited for the generation of ultrasonic vibrations through transducerassembly (121312).

Blade (121460) of the present example is operable to vibrate atultrasonic frequencies in order to effectively cut through and sealtissue. Blade (121460) is positioned at the distal end of an acousticdrivetrain. This acoustic drivetrain includes transducer assembly(121312) and an acoustic waveguide (not shown). The acoustic waveguidecomprises a flexible portion (not shown) similar to flexible portion(166) described above with respect to instrument (10). Transducerassembly (121312) includes a set of piezoelectric discs (not shown)located proximal to a horn (not shown) of the waveguide. Thepiezoelectric discs are operable to convert electrical power intoultrasonic vibrations, which are then transmitted along the waveguide toblade (121460) in accordance with known configurations and techniques.By way of example only, this portion of the acoustic drivetrain may beconfigured in accordance with various teachings of various referencesthat are cited herein.

Shaft assembly (121330) of the present example extends distally fromhandle assembly (121320). Unless otherwise noted herein, shaft assembly(121330) is substantially the same as shaft assembly (30) describedabove with respect to instrument. For instance, shaft assembly (121330)includes an articulation section (121430), which is located at a distalportion of shaft assembly (121330), with end effector (121340) beinglocated distal to articulation section (121430). As shown in FIG. 156, aknob (121331) is secured to a proximal portion of shaft assembly(121330). Knob (121331) is rotatable relative to body (121322), suchthat shaft assembly (121330) is rotatable about the longitudinal axisdefined by shaft assembly (121330), relative to handle assembly(121320). Such rotation may provide rotation of end effector (121340),articulation section (121430), and shaft assembly (121330) unitarily. Ofcourse, rotatable features may simply be omitted if desired.

Articulation section (121430) is substantially the same as articulationsection (130) described above with respect to instrument (10), unlessotherwise note herein. For instance, articulation section (121430) isoperable to selectively position end effector (121340) at variouslateral deflection angles relative to a longitudinal axis defined byshaft assembly (121430). Like with articulation section (130),articulation section (121430) is driven by a pair of articulation bands(121440, 121442) disposed within articulation section (121430) andextending through shaft assembly (121330). When articulation bands(121440, 121142) translate longitudinally in an opposing fashion, thiswill cause articulation section (121430) to bend, thereby laterallydeflecting end effector (121340) away from the longitudinal axis ofshaft assembly (121330) from a straight configuration to an articulatedconfiguration. In particular, end effector (121340) will be articulatedtoward the articulation band (121440, 121442) that is being pulledproximally. During such articulation, the other articulation band(121440, 121442) may be pulled or pushed distally.

Instrument further includes an articulation control assembly (121400)that is secured to a proximal portion of shaft assembly (121330).Articulation control assembly (121400) comprises a housing (121410) anda rotatable knob (121420). Like with articulation control assembly (100)described above, rotatable knob (121420) is configured to rotaterelative to housing (121410) to drive articulation bands (121440,121442) in opposing longitudinal directions. For instance, rotation ofknob (121420) in a first direction causes distal longitudinaltranslation of articulation band (121440), while simultaneously causingproximal longitudinal translation of articulation band (121442).Rotation of knob (121420) in a second direction causes proximallongitudinal translation of articulation band (121440), whilesimultaneously causing distal longitudinal translation of articulationband (121442). Thus, it should be understood that rotation of rotationknob (121420) causes articulation of articulation section (121430).

Unlike instrument (10) described above, instrument (121310) of thepresent example further includes a tensioning assembly (121500).Tensioning assembly (121500) is generally operable as a over-centertoggle mechanism to directly apply tension to articulation bands(121440, 121442) and to maintain such tension. In particular, as canbest be seen in FIGS. 156 and 157, tensioning assembly (121500)comprises a lever arm (121510) and a collar (121520) disposed aboutshaft assembly (121330). Lever arm (121510) is attached to housing(121410) of actuation control assembly (121400) at an integralattachment yoke (121415) of housing (121410). Lever arm (121510) isconnected to attachment yoke (121415) via a pin (121511) that isconfigured to permit lever arm (121510) to pivot relative to attachmentyoke (121415). As will be described in greater detail below, lever arm(121510) is generally configured to pivot relative to attachment yoke(121415) as an over-center toggle mechanism to drive collar (121520)proximally or distally.

Lever arm (121510) is connected to collar (121520) by two links (121512,121514) extending between lever arm (121510) and collar (121520). Eachlink (121512, 121514) is pivotably connected to lever arm at a pin(121515) disposed near the center of lever arm (121510). Each link(121512, 121514) also pivotably connects to collar (121520) at arespective pivotal coupling (121521, 121522). Both pin (121515) andpivotal couplings (121521, 121522) allow each link to pivot as lever arm(121510) and collar (121520) are moved.

As can best be seen in FIGS. 157 and 158, collar (121520) includes apair of inwardly extending armatures (121524) (only a single armature isshown) that extend from collar (121520) and into shaft assembly (121330)through a pair of slots (121333) in shaft assembly (121330). Eacharmature (121524) connects to a respective articulation band (121440,121442). In particular, each articulation band (121440, 121442) includesa slot that receives a corresponding armature (121524). The slots andarmatures (121524) are configured such that articulation bands (121440,121442) may move freely in opposing longitudinal directions when collar(121520) is in the distal position shown in FIG. 159. However, whencollar (121520) is moved to the proximal position shown in FIG. 160 asdescribed in greater detail below, the and armatures (121524) areconfigured such that armatures (121524) reach the proximal ends of thoseslots, thereby pulling proximally on articulation bands (121440, 121442)to provide tension in articulation bands (121440, 121442). The oppositeend of each armature (121524) is integral or fixedly secured to an innerring (121526) disposed within collar (121520) Inner ring (121526) isconfigured to freely rotate within collar (121520) while stilltransferring any translation of collar (121520) to each armature(121524). Such a feature may be desirable because when collar (121520)includes such a feature, collar (121520) may remain stationary whileshaft assembly (121330) is rotated.

As another exemplary configuration, collar (121520) may include a camfeature that provides selective engagement between collar (121520) andarticulation bands (121440, 121442). For instance, when such a camfeature is in a first position, collar (121520) may be disengaged fromarticulation bands (121440, 121442), such that articulation bands(121440, 121442) may move freely in opposing longitudinal directionswhen the cam feature is in the first position. When the cam feature ismoved (e.g., rotated, slid, etc.) to a second position, the cam featuremay provide engagement between collar (121520) and articulation bands(121440, 121442), such that longitudinal motion of collar (121520)provides corresponding, simultaneous longitudinal motion of articulationbands (121440, 121442). Other suitable structures and relationships thatmay be provided between collar (121520) and articulation bands (121440,121442) will be apparent to those of ordinary skill in the art in viewof the teachings herein.

An exemplary use of tensioning assembly (121500) is shown in FIGS. 159and 160. In particular, tensioning assembly (121500) may initially be ina non-tensioning or relaxed position. In such a position, lever arm(121510) is pivotably disposed upwardly such that pin (121515) isdisposed above pin (121511). With lever arm (121510) positionedupwardly, collar (121520) is pushed to a distal position relative toshaft assembly (121330) by each link (121512, 121514). Because collar(121520) is attached to articulation bands (121440, 121442) viaarmatures (121524), articulation bands (121440, 121442) are in anon-tensioned or relaxed state when collar (121520) is in the distalposition. Accordingly, articulation bands (121440, 121442) may be usedto articulate articulation section (121430) via articulation controlassembly (121400) as described above when collar (121520) is in thedistal position.

To transition tensioning assembly (121500) to a tensioning position, anoperator may pivot lever arm (121510) downwardly to the position shownin FIG. 160. As can be seen, when lever arm (121510) is forceddownwardly, each link (121512, 121514) pulls collar (121520) proximallyrelative to shaft assembly (121330). Because collar (121520) is attachedto each articulation band (121440, 121442), collar (121520) willsimultaneously pull each articulation band (121440, 121442)correspondingly proximally. Thus, collar (121520) will act to applytension to each articulation band (121440, 121442) as it is pulledproximally by lever arm (121510).

With lever arm (121510) in the position shown in FIG. 160, tensioningassembly (121500) is in a tensioned position. In the tensioned position,collar (121520) is at its furthest proximal position relative to shaftassembly (121330) and articulation bands (121440, 121442) arecorrespondingly fully tensioned. Additionally, lever arm (121510) ispositioned such that pin (121515) is disposed below pin (121511).Because of this and the tensioning force generated between lever arm(121510) and collar (121520), lever arm (121510) is generally fixed inthe tensioned position, such that tensioning assembly (121500) providesan over-center toggle. Accordingly, should an operator desire to returntensioning assembly (121500) to the non-tensioning or relaxed position,the operator will need to pivot lever arm (121510) upwardly back to theposition shown in FIG. 156. While the present example includes anover-center toggle feature to maintain lever arm (121510) in thetensioned position, any other suitable feature or mechanism may be used.Alternatively, in other examples such a feature may simply be omitted.

In one some alternative versions of instrument (121400), collar (121520)is omitted. In some such versions, yoke (121415) is an integral featureof body (121322) of handle assembly (121320), such that lever arm(121510) is pivotably coupled directly to handle assembly (121320). Inaddition, in some such versions, the distal ends of links (121512,121514) are pivotably coupled directly with housing (121410) ofarticulation control assembly (121400). Such an example may operatesimilar to the example of instrument (121100) described above. Thus,when lever arm (121510) is pivoted to an upward position, articulationcontrol assembly (121400) is in a distal position and articulation bands(121440, 121442) are free to translate in order to provide articulationof articulation section (121430). When lever arm (121510) is pivoted toa downward position, articulation control assembly (121400) is in aproximal assembly, pulling articulation bands (121440, 121442) such thatarticulation bands (121440, 121442) are in tension, thereby effectivelyrigidizing articulation section (121430) (e.g., when articulationsection is in a straight or non-articulated state). Other suitablevariations will be apparent to those of ordinary skill in the art inview of the teachings herein.

XIV. ULTRASONIC SURGICAL INSTRUMENT WITH MOVABLE RIGIDIZING MEMBER

As noted above, in some versions of instrument (10) it may be desirableto provide features that are configured to selectively provide rigidityto articulation section (130). For instance, because of various factorssuch as manufacturing tolerances, design limitations, materiallimitations, and/or other factors, some versions of articulation section(130) may be susceptible to some “play” or other small movement of thearticulation section despite being relatively fixed in a given position,such that articulation section (130) is not entirely rigid. It may bedesirable to reduce or eliminate such play in articulation section(130), particularly when articulation section (130) is in a straight,non-articulated configuration. Features may thus be provided toselectively rigidize articulation section (130). Various examples offeatures that are configured to selectively provide rigidity toarticulation section (130) and/or to limit or prevent inadvertentdeflection of end effector (40) will be described in greater detailbelow. Other examples will be apparent to those of ordinary skill in theart according to the teachings herein. It should be understood that theexamples of shaft assemblies and/or articulation sections describedbelow may function substantially similar to shaft assembly (30)discussed above.

It should also be understood that articulation section (130) may stillbe at least somewhat rigid before being modified to include the featuresdescribed below, such that the features described below actually justincrease the rigidity of articulation section (130) rather thanintroducing rigidity to an otherwise non-rigid articulation section(130). For instance, an articulation section (130) in the absence offeatures as described below may be rigid enough to substantiallymaintain a straight or articulated configuration; yet may still provide“play” of about 1 mm or a fraction thereof such that the alreadyexisting rigidity of articulation section (130) may be increased. Thus,terms such as “rigidize,” “provide rigidity,” and “providing rigidity”shall be understood to include just increasing rigidity that is alreadypresent in some degree. The terms “rigidize,” “provide rigidity,” and“providing rigidity” should not be read as necessarily requiringarticulation section (130) to completely lack rigidity before therigidity is “provided.”

It should also be understood that “rigidizing” articulation section(130) may be viewed as more than merely locking articulation section(130). For instance, while articulating sections in some conventionalinstruments may include a locking feature that selectively locks thearticulation section, such instruments may still demonstrate some degreeof play in the articulation section, even when the articulation sectionpurports to be in a locked state. By further “rigidizing” thearticulation section as described herein, that play would be removedfrom the locked articulation section. Thus, terms such as “rigidizing”and “locking” should not be read as being synonymous.

Various examples of features that are configured to selectively rigidizearticulation section (130) are described in greater detail below.Various other examples will be apparent to those of ordinary skill inthe art in view of to the teachings herein.

A. Articulation Section with Movable Sheath

FIGS. 161 and 162 show a version of shaft assembly (30) that is modifiedto include a movable sheath (13210), which is slidably disposed aboutproximal outer sheath (32). Sheath (13210) is generally cylindrical inshape and is configured to fit over outer sheath (32). In particular,sheath (13210) comprises a tapered open distal end (13212) and a taperedopen proximal end (13214). Accordingly, sheath (13210) is a generallyhollow tube that surrounds outer sheath (32). Each end (13212, 13214)defines an inner diameter that is closely matched to the outer diameterof outer sheath (32). Such a relationship between the inner diameter ofsheath (13210) and outer sheath (32) may be desirable because such arelationship may prevent movement of articulation section (130) whensheath (13210) is disposed over articulation section (130). Although theinner diameter of sheath (13210) is similar to the outer diameter ofouter sheath (32) it should be understood that the inner diameter ofsheath (13210) may still be large enough relative to the outer diameterof outer sheath (32) to permit sheath (13210) to slide relative to outersheath (32). As will be described in greater detail below, suchslidability is desirable because it may permit sheath (13210) to beselectively positioned over articulation section (130).

Sheath (13210) is comprised of a generally rigid thin walledbiocompatible material such as titanium, stainless steel, rigid plastic,and/or any other suitable material(s). Because distal and proximal ends(13212, 13214) of sheath (13210) are tapered, the wall thickness ofsheath (13210) varies by length. Such a taper may prevent sheath (13210)from being snagged on a trocar or other surgical port as shaft assembly(30) is inserted into and withdrawn from the trocar or other port. Itshould be understood that such a taper is merely optional, and in someexamples sheath (13210) may have a uniform thickness along the fulllength of sheath (13210).

FIGS. 161 and 162 show an exemplary use of sheath (13210). As can beseen in FIG. 161, sheath (13210) may initially be disposed in a firstposition. In the first position, sheath (13210) is disposed proximallyof articulation section (130). In such a position, articulation section(130) is free to articulate as described above in response to anoperator acting upon articulation control assembly (100).

When an operator desires to rigidize articulation section (130) in afixed, straight position, an operator may do so by grasping sheath(13210) and translating sheath (13210) distally to the position shown inFIG. 162. The position shown in FIG. 162 corresponds to sheath (13210)being in a second position. In the second position, sheath (13210) isdisposed over articulation section (130) with distal end (13212)disposed over at least a portion of distal outer sheath (33) andproximal end (13214) over at least a portion of proximal outer sheath(32). When in the second position, the inner diameter of sheath (13210)engages distal outer sheath (33), articulation section (130) andproximal outer sheath (32) to prevent substantially all articulationand/or other movement of articulation section (130). In other words,sheath (13210) rigidizes articulation section (130) when sheath (13210)is disposed in the second position.

Although sheath (13210) of the present example is described herein asbeing manually translatable by an operator, it should be understood thatin other examples sheath (13210) may be translatable by other means. Forinstance, in some examples sheath (13210) may further comprise certainactuation components that are in communication with articulation bands(140, 142). In examples incorporating such actuation components, theactuation components are responsive to movement of articulation bands(140, 142) such that sheath (13210) is automatically transitionedbetween the first and second positions by movement of articulation bands(140, 142) through certain predetermined positions. Additionally or inthe alternative, sheath (13210) may also be spring loaded toautomatically transition sheath (13210) from the first position to thesecond position. As yet another merely illustrative alternative, sheath(13210) may be actuated by knob (120), some other user input feature atarticulation control assembly (100), and/or some other feature of handleassembly (20). Still other suitable mechanisms for transitioning sheath(210) between the first and second positions will be apparent to thoseof ordinary skill in the art in view of the teachings herein.

B. Articulation Section with Movable Sheath and Sheath Securing Features

FIGS. 163-165 show a version of shaft assembly (30) that is modified toinclude another movable sheath (13310), which is slidably disposed aboutproximal outer sheath (32). Sheath (13310) is generally cylindrical inshape and is configured to fit over outer sheath (32). In particular,sheath (13310) comprises a tapered open distal end (13312), a taperedopen proximal end (13314), and a grip portion (13316) disposed distallyof proximal end (13314). Accordingly, sheath (13310) is a generallyhollow tube that surrounds outer sheath (32). Each end (13312, 13314)defines an inner diameter of sheath (13310) that is closely matched tothe outer diameter of outer sheath (32). Such a relationship between theinner diameter of sheath (13310) and outer sheath (32) may be desirablebecause such a relationship may prevent movement of articulation section(130) when sheath (13310) is disposed over articulation section (130).Although the inner diameter of sheath (13310) is similar to the outerdiameter of outer sheath (32) it should be understood that the innerdiameter of sheath (13310) may still be large enough relative to theouter diameter of outer sheath (32) to permit sheath (13310) to sliderelative to outer sheath. As will be described in greater detail below,such slidability is desirable because it may permit sheath (13310) to beselectively positioned over articulation section (130).

Grip portion (13316) is generally configured to facilitate grasping ofsheath (13310) by an operator. Grip portion (13316) of sheath comprisesa plurality of grip features (13317). Grip features (13317) of thepresent example are shown as spaced-apart indentations in the outerdiameter of sheath (13310). In other examples, grip features (13317) areformed by integral protrusions or separately secured protrusions. Inexamples utilizing protrusions, it should be understood that theprotrusions protrude from sheath (13310) may be fixed by the innerdiameter of a trocar or other port that instrument (10) may be used inconjunction with. It should also be understood that grip portion (13312)is merely optional, such that grip portion (13312) is omitted in someversions.

Sheath (13310) is comprised of a generally rigid thin walledbiocompatible material such as titanium, stainless steel, rigid plastic,or etc. Because distal and proximal ends (13312, 13314) of sheath(13310) are tapered, the wall thickness of sheath (13310) varies bylength. Such a taper may prevent sheath (13310) from being snagged on atrocar or other surgical port as shaft assembly (30) is inserted intoand withdrawn from the trocar or other port. It should be understoodthat such a taper is merely optional, and in some examples sheath(13310) may have a uniform thickness along the full length of sheath(13310).

Distal outer sheath (33) and proximal outer sheath (32) in the presentexample each include a flared stop member (13320, 13326). In particular,a distal stop member is positioned on distal outer sheath (33) and aproximal stop member (13326) is positioned on proximal outer sheath(33). Each stop member (13320, 13326) is unitarily secured to thecorresponding sheath (32, 33). Each stop member (13320, 13326) isgenerally frustoconical in shape, with a maximum outer diameter that isgreater than the inner diameter of sheath (13310) such that stop members(13320, 13326) are configured to engage with sheath (13310) and therebyrestrict longitudinal movement of sheath (13310). In the presentexample, each stop member (13320, 13326) is overmolded onto eachrespective sheath (32, 33) and comprises a resilient material such as asoft plastic or rubber. In some other examples, each stop members(13320, 13326) is unitarily formed with each respective sheath (32, 33).

As will be described in greater detail below, sheath (13310) isgenerally slidable and into engagement with either distal stop member(13320) or proximal stop member (13326). Thus, distal stop member(13320) is positioned such that an engagement end (13322) is positionedproximally, while proximal stop member (13326) is positioned such thatan engagement end (13328) is positioned distally. Engagement end (13322)is sized for snug receipt within sheath (13310), such that distal stopmember (13320) may releasably hold sheath (13310) in a distal positionthrough friction between engagement end and the interior of sheath(13310). Similarly, engagement end (13328) is sized for snug receiptwithin sheath (13310), such that proximal stop member (13326) mayreleasably hold sheath (13310) in a proximal position through frictionbetween engagement end and the interior of sheath (13310). The enlargeddistal end of distal stop member (13320) will restrict distal movementof sheath (13310), while the enlarged proximal end of proximal stopmember (13326) will restrict proximal movement of sheath (13310).

FIGS. 163-165 show an exemplary use of sheath (13310). As can be seen inFIG. 163, sheath (13310) may initially be disposed in a first position.In the first position, sheath (13310) is disposed proximally ofarticulation section (130) yet distally of proximal stop member (13326).In such a position, articulation section (130) is free to articulate asdescribed above in response to an operator acting upon articulationcontrol assembly (100). Further, sheath (13310) is free from both stopmembers (13320, 13326) such that sheath (13310) is freely movablebetween stop members (13320, 13326).

When sheath (13310) is in the first position, an operator may optionallylock sheath (13310) in a second position, or advance sheath (13310) to athird position. FIG. 164 shows sheath (13310) in the second position. Ascan be seen, the second position corresponds to sheath (13310) beingdisposed over proximal outer sheath (32) and engaged with proximal stopmember (13326). It should be understood that the second positioncorresponds to the furthest proximal position of sheath (13310). Inparticular, stop member (13326) prevents further proximal movement ofsheath (13310). Additionally, stop member (13326) resiliently lockssheath (13310) in position by resiliently engaging the inner diameter ofsheath (13310). In other words, sheath (13310) compresses engagement end(13328) and thereby creates friction that releasably holds sheath(13310) in place.

When an operator desires to rigidize articulation section (130) in afixed, straight position, the operator may do so by grasping sheath(13310) and translating sheath (13310) distally to the position shown inFIG. 165 from either the first position or the second position. Theposition shown in FIG. 165 corresponds to sheath (13310) being in thethird position. In the third position, sheath (13310) is disposed overarticulation section (130) with distal end (13312) disposed over atleast a portion of distal outer sheath (33) and proximal end (13314)over at least a portion of proximal outer sheath (32). Additionally,distal end (13312) engages at least a portion of distal stop member(13320). Sheath (13310) compresses engagement end (13322) and therebycreates friction that releasably holds sheath (13310) in place. Inaddition, stop member (13320) prevents further distal movement of sheath(13310). When in the third position, the inner diameter of sheath(13310) engages distal outer sheath (33), articulation section (130),and proximal outer sheath (32) to prevent substantially all articulationand/or movement of articulation section (130). In other words, sheath(13310) rigidizes articulation section (130) when sheath (13310) isdisposed in the third position.

Like with sheath (13210) described above, sheath (13310) of the presentexample may also be translatable by other non-manual means. Forinstance, in some examples sheath (13310) may further comprise certainactuation components that are in communication with articulation bands(140, 142). In examples incorporating such actuation components, theactuation components are responsive to movement of articulation bands(140, 142) such that sheath (13310) is automatically transitionedbetween the first and second positions by movement of articulation bands(140, 142) through certain predetermined positions. Additionally or inalternative, sheath (13310) may also be spring loaded to automaticallytransition sheath (13310) from the first position to the secondposition. As yet another merely illustrative alternative, sheath (13310)may be actuated by knob (120), some other user input feature atarticulation control assembly (100), and/or some other feature of handleassembly (20). Still other suitable mechanisms for transitioning sheath(13310) between the first and second positions will be apparent to thoseof ordinary skill in the art in view of the teachings herein.

C. Articulation Section with Rotatable Locking Sheath

FIGS. 166-170 show a version of shaft assembly (30) that is modified toinclude a rotatable sheath (13410), which is rotatably disposed aboutarticulation section (130). Rotatable sheath (13410) is generallytubular in structure and comprises two tab members (13420, 13430) ofunitary construction with sheath (13410). Tab members (13420, 13430) areformed by slits (13420, 13430) cut (13421, 13431) within sheath (13410)to define a longitudinal portion (13424, 13434) and a transverse portion(13426, 13436) of each tab member (13420, 13430), such that each tabmember (13420, 13430) has a “T” shape. As can be seen in FIG. 167, thethickness of each tab member (13420, 13430) expands from transverseportion (13426, 13436) to longitudinal portion (13424, 13434) such thatat least a portion of each tab member (13420, 13430) extends into theinner diameter of sheath (13410). As will be described in greater detailbelow, the increased thickness of each longitudinal portion (13424,13434) is configured to engage with retention collars (133) ofarticulation section (130) to prevent articulation of articulationsection (130). In some versions, each tab member (13420, 13430) has auniform thickness and tab members (13420, 13430) are simply resilientlybiased to extend inwardly into the inner diameter of sheath (13410). Forinstance, transverse portions (13426, 13436) may be bent inwardly toresiliently position longitudinal portions (13424, 13434) into the innerdiameter of sheath (13410).

Sheath (13410) further comprises a generally flexible material such thatsheath (13410) is configured to bend as articulation section (130) isarticulated. Although the material of sheath (13410) is generallyflexible, it should also be understood that the material of sheath(13410) is somewhat rigid. As will be described in greater detail below,tab members (13420, 13430) are configured to engage retention collars(133) of articulation section (130) to selectively prevent articulationof articulation section (130). Accordingly, sheath (13410) is comprisedof a material of sufficient column strength such that tab members(13420, 13430) resist buckling when compressed between retention collars(133). Sheath (13410) may comprise any suitable material such asbiocompatible polymers and/or any other material(s) as will be apparentto those of ordinary skill in the art in view of the teachings herein.

FIGS. 166, 168, and 169-170 show an exemplary use of sheath (13410). Inparticular, as can be seen in FIGS. 166 and 168, sheath (13410) isinitially in a first angular position. When sheath (13410) is in thefirst angular position, longitudinal portions (13424, 13434) of each tabmember (13420, 13430) are aligned with an articulation plane throughwhich the central longitudinal axis of shaft assembly (30) articulates.As can best be seen in FIG. 168, when sheath (13410) is in the firstposition, longitudinal portions (13424, 13434) of each tab member(13420, 13430) are positioned between each retention collar (133) alongthe articulation plane. Accordingly, longitudinal portions (13424,13434) are positioned to block any articulation of articulation section(130) because longitudinal portions (13424, 13434) prevent retentioncollars (133) from moving closer to one another. Therefore, sheath(13410) acts as a locking member to increase the rigidity ofarticulation section (130) when sheath (13410) is in the first angularposition.

To unlock articulation section (130) for articulation, an operator mayrotate sheath (13410) 90° about the longitudinal axis of shaft assembly(30), relative to the rest of shaft assembly (30), to a second angularposition. As can be seen in FIGS. 169 and 170, when sheath (13410) is inthe second angular position, longitudinal portions (13424, 13434) areoriented perpendicularly from the articulation plane of articulationsection (130). Thus, although longitudinal portions (13424, 13434)remain disposed between retention collars (133) of articulation section(130), articulation section (130) is permitted to articulate becauselongitudinal portions (13424, 13434) are not positioned to blockmovement of retention collars (133) along the articulation plane asarticulation section (130) is articulated. Moreover, because sheath(13410) is relatively flexible, sheath (13410) itself does not preventarticulation of articulation section (130). Therefore, sheath (13410)acts to permit articulation of articulation section (130) when sheath(13410) is in the second angular position.

By way of example only, an operator may selectively transition sheath(13410) between the first and second angular positions by simplygrasping sheath (13410) and rotating sheath (13410) about thelongitudinal axis of shaft assembly (30) while holding the rest of shaftassembly (30) stationary. Alternatively, sheath (13410) may be actuatedbetween the first and second angular positions via a user input featurethat is incorporated into articulation control assembly (100) and/orsome other feature of handle assembly (20). Various suitable ways inwhich sheath (13410) may be actuated will be apparent to those ofordinary skill in the art in view of the teachings herein.

FIG. 171 shows an exemplary alternative sheath (13510) that operatessimilarly to sheath (13410) and may be readily incorporated into shaftassembly (30) of instrument (10). In the present example, sheath (13510)is positioned over articulation section (130) as described above. Insome versions, retention collars (133) are omitted when sheath (13510)is incorporated into shaft assembly (30). As can be seen, sheath (13510)is comprised of a plurality of segments (13512, 13518, 13524) that aredisposed over articulation section (130). In particular, segments(13512, 13518, 13524) form a generally tubular structure that isconfigured to bend in a single lateral direction as indicated by arrow(13530), but resist bending in other directions that are generallyoblique or perpendicular to arrow (13530).

Segments (13512, 13518, 13524) of the present example comprise two endsegments (13512, 13524) and three intermediate segments (13518). Eachend segment (13512, 13524) includes an end portion (13514, 13526) and aconnecting portion (13516, 13528). End portions (13514, 13526) aregenerally circular in cross-section and are configured to receive distalouter sheath (33) and proximal outer sheath (32), respectively.Connecting portions (13516, 13528) are configured to abut acorresponding intermediate segment (13518). Each connecting portion(13516, 13528) defines an indentation (13517, 13529) therein. As will bedescribed in greater detail below, each indentation (13517, 13529) isgenerally configured to cooperate with corresponding indentation (13523)of an adjacent intermediate segment (13518) to thereby permitarticulation of sheath (13510) along the lateral direction indicated byarrow (13530).

Each intermediate segment (13518) of the present example issubstantially the same. Although the present example is shown ascomprising three intermediate segments (13518), it should be understoodthat any suitable number of intermediate segments (13518) may be used.Further, in some examples intermediate segments (13518) may be omittedand end segments (13512, 13524) may simply be adjacent to each other.Each intermediate segment (13518) is generally symmetrical with a distalportion (13520) and a proximal portion (13522). Each portion (13520,13522) defines an indentation (13523) and abuts a corresponding adjacentsegment (13512, 13518, 13524). Each indentation (13523) is aligned witheither an adjacent indentation (13523) of another intermediate segment(13518) or an adjacent indentation (13517, 13529) of end segments(13512, 13524).

Segments (13512, 13518, 13524) are connected to each other sequentiallyto form the tubular structure of sheath (13510). Segments (13512, 13518,13524) are connected to each other such that each segment (13512, 13518,13524) is movable relative to an adjacent segment (13512, 13518, 13524).For instance, suitable connections may include wire connections, thinwalled flexible integral members, hinge members, or any other suitablestructures as will be apparent to those of ordinary skill in the art inview of the teachings herein. Regardless of the particular connectionused, each segment (13512, 13518, 13524) is aligned with an adjacentsegment (13512, 13518, 13524) such that all indentations (13517, 13523,13529) are aligned with each other along a linear path that is generallyparallel to the longitudinal axis of shaft assembly (30). It should beunderstood that the alignment of indentations (13517, 13523, 13529) maypermit flexibility of sheath (13510) along the linear path of alignmentbecause each indentation (13517, 13523, 13529) provides space for eachsegment to pivot relative to the other. In contrast, where each segment(13512, 13518, 13524) abuts another without the presence of indentation(13517, 13523, 13529), flexibility of sheath (13510) is blocked becauseeach segment (13512, 13518, 13524) has little to no space to moverelative to other segments (13512, 13518, 13524).

FIGS. 171 and 172 show an exemplary use of sheath (13510). Inparticular, FIG. 171 shows sheath (13510) in a first angular position.In the first angular position, indentations (13517, 13523, 13529) ofeach segment (13512, 13518, 13524) of sheath (13510) are aligned alongthe articulation plane of shaft assembly (30) as indicated by arrow(13530). Thus, when sheath (13510) is in the first position, sheath(13510) permits articulation of articulation section (130). Toarticulate articulation section (130), an operator may actuatearticulation control assembly (100) as described above.

Once an operator desires to lock articulation section (130) in astraight position, the operator may first transition articulationsection (130) to the straight configuration using articulation controlassembly (100) as described above. Once articulation section (130) is inthe straight configuration, the operator may rotate sheath (13510) 90°about the longitudinal axis of shaft assembly (30), relative to the restof shaft assembly (30), to a second angular position as shown in FIG.172. As can be seen, when sheath (13510) is rotated to the secondangular position, indentations (13517, 13523, 13529) of each segment(13512, 13518, 13524) of sheath (13510) are aligned in a position thatis normal to the articulation plane of shaft assembly (30). As describedabove, sheath (13510) is only bendable in the direction of indentations(13517, 13523, 13529). Accordingly, when indentations (13517, 13523,13529) are positioned normal to the articulation plane of shaft assembly(30), sheath (13510) prevents articulation of articulation section (130)because segments (13512, 13518, 13524) are incapable of moving relativeto each other along the articulation plane of articulation section (130)when sheath (13510) is in the second angular position. Therefore, whensheath (13510) is positioned in the second angular position,articulation section (130) is locked from articulation and/or increasedin rigidity due to the angular positioning of sheath (13510).

By way of example only, an operator may selectively transition sheath(13510) between the first and second angular positions by simplygrasping sheath (13510) and rotating sheath (13510) about thelongitudinal axis of shaft assembly (30) while holding the rest of shaftassembly (30) stationary. Alternatively, sheath (13510) may be actuatedbetween the first and second angular positions via a user input featurethat is incorporated into articulation control assembly (100) and/orsome other feature of handle assembly (20). Various suitable ways inwhich sheath (13510) may be actuated will be apparent to those ofordinary skill in the art in view of the teachings herein.

D. Articulation Section with Complementary Locking Shafts

FIGS. 173-175 show an exemplary alternative sheath assembly (13610) thatmay be readily incorporated into shaft assembly (30) described above. Inexamples where sheath assembly (13610) is incorporated into shaftassembly (30), sheath assembly (13610) may be disposed aroundarticulation section (130) to thereby selectively rigidize articulationsection (130). Sheath assembly (13610) is longitudinally fixed aboutarticulation section (130). Sheath assembly (13610) comprises an innersheath (13612) disposed coaxially within an outer sheath (13620). Aswill be described in greater detail below, sheaths (13612, 13620) areconfigured to cooperate to selectively rigidize articulation section(130). In the present example sheaths (13612, 13620) are each about0.0075″ thick, although any suitable thickness may be used. Forinstance, in some examples sheaths (13612, 13620) range from about0.005″ to about 0.010″ in wall thickness.

As can be seen in FIG. 173 outer sheath (13620) comprises a plurality ofopenings (13622) on the exterior of outer sheath (13620). In particular,openings (13622) are all substantially the same and have an elongateovular or elliptical shape. As will be described in greater detailbelow, openings (13622) are generally configured to locally increase theflexibility of outer sheath (13620) in the region of outer sheath(13620) where openings (13622) are positioned. Although not shown, itshould be understood that openings (13622) extend laterally though outersheath (13620) and thus are also disposed on the opposite outer wall ofouter sheath (13620). Such a feature is configured to increase the localflexibility of outer sheath (13620) because openings (13622) on one sidemay expand while openings (13622) on another side may contract as outersheath (13620) bends along an articulation plane. It should beunderstood that openings (13620) are configured to allow outer sheath(13620) to bend along just one plane.

As best seen in FIG. 174, inner sheath (13612) also comprises aplurality of openings (13614) on the exterior of inner sheath (13612).Openings (13614) are similar to openings (13622) described above. Forinstance, openings (13614) have a generally elongate ovular orelliptical shape. Furthermore, openings (13614) are likewise configuredto locally increase the flexibility of inner sheath (13612) in theregion of inner sheath (13612) where openings (13614) are positioned.However, in contrast to openings (13622), openings (13614) are smallerin scale proportionally to the smaller diameter of inner sheath (13612).Although smaller in scale, openings (13614) are positioned to align withopenings (13622) of outer sheath (13620). Although the present exampleis shown as including five sets of openings (13614, 13622), it should beunderstood that in other examples any suitable number of openings(13614, 13622) may be used. Openings (13614) are configured to allowinner sheath (13612) to bend along a single plane, with openings (13614)on one side of inner sheath (13612) expanding while openings (13614) onthe other side of inner sheath (13612) contracting as inner sheath(13612) bends along the plane. In the present example, inner sheath(13612) is fixedly secured about articulation section (130) such thatinner sheath (13612) does not rotate about articulation section (130).However, outer sheath (13620) is rotatable about inner sheath (13612)and thus about articulation section (130).

FIGS. 173 and 175 show an exemplary use of sheath assembly (13610).Initially, sheath assembly (13610) may be in a first configuration asshown in FIG. 173. As can be seen, when sheath assembly (13610) is inthe first configuration, inner and outer sheaths (13612, 13620) areangularly aligned such that openings (13614) of inner sheath (13612) arealigned with openings (13622) of outer sheath (13620). When openings(13614, 13622) are aligned, the respective bending planes of inner andouter sheaths (13612, 13620) are aligned such that inner and outersheaths (13612, 13620) are together bendable along their common bendingplane. Thus, in the first position sheath assembly (13610) permitsarticulation of articulation section (130) when incorporated into shaftassembly (30) described above.

If an operator desires to make sheath assembly (13610) rigid, such aswhen sheath assembly (13610) is incorporated into shaft assembly (30)described above, the operator may rotate outer sheath (13620) relativeto inner sheath (13612) 90° about the longitudinal axis of sheathassembly (13610) to a second angular position shown in FIG. 175. As canbe seen, in the second position, outer sheath (13620) has been rotatedapproximately 90° such that openings (13622) of outer sheath (13620) areangularly offset from openings (13614) of outer sheath (13612). Whenopenings (13614, 13622) are angularly offset by 90°, any flexibilityachieved by use of openings (13614, 13622) is lost because solidportions of sheath (13612) block flexibility of openings (13622) andsolid portions of sheath (13620) block flexibility of openings (13614).Therefore, when outer sheath (13620) is in the second angular position,sheath assembly (13610) is used to lock and/or increase the rigidity ofarticulation section (130).

Although the second position is shown in FIG. 175 as outer sheath(13620) being rotated approximately 90° from the position of outersheath (13620) in the first position, it should be understood that outersheath (13620) may be rotated to other positions to achieve the sameoutcome of stiffening sheath assembly (13610). For instance, in someexamples outer sheath (13620) may be rotated as little as 15° beforecausing stiffening of sheath assembly (13610). Of course, in otherexamples outer sheath (13620) may be rotated even further than 90°.Additionally, although outer sheath (13620) is described herein as beingrotated, in other examples inner sheath (13612) may be rotated instead,or both sheaths (13612, 13620) may be rotated simultaneously atdifferent rates to achieve the same result. In still other examples,sheaths (13612, 13620) may not be rotated at all. Instead, one sheaths(13612, 13620) may be translated longitudinally relative to the othersheaths (13612, 13620) in order to position openings (13622) of outersheath (13620) at longitudinal positions that are offset from thelongitudinal positions of openings (13614) of outer sheath (13612), suchthat sheaths (13612, 13620) are out of phase with each other.

Although sheath assembly (13610) of the present example is describedherein as being manually actuated by an operator, it should beunderstood that in other examples sheath assembly (13610) may beactuated by other means. For instance, in some examples sheath assembly(13610) may further comprise certain actuation components that are incommunication with articulation bands (140, 142). In examplesincorporating such actuation components, the actuation components areresponsive to movement of articulation bands (140, 142) such that outersheath (13620) is automatically transitioned between the first andsecond angular positions by movement of articulation bands (140, 142)through certain predetermined positions. Additionally or in thealternative, sheath assembly (13610) may also be spring loaded toautomatically transition outer sheath (13620) from the first position tothe second position. As yet another merely illustrative alternative,sheath assembly (13610) may be actuated by knob (120), some other userinput feature at articulation control assembly (100), and/or some otherfeature of handle assembly (20). Still other suitable mechanisms fortransitioning outer sheath (13620) between the first and second angularpositions will be apparent to those of ordinary skill in the art in viewof the teachings herein.

E. Articulation Section with Interlocking Coil Sheath

FIGS. 176 and 177 show a version of shaft assembly (30) that is modifiedto include a sheath assembly (13710), which is generally configured toselectively rigidize articulation section (130). In the present example,at least a portion of sheath assembly (13710) is disposed aroundarticulation section (130) to thereby permit sheath assembly 13(710) toselectively rigidize articulation section (130). Sheath assembly (13710)comprises a first coil member (13712) with a second coil member (13720)interlockingly engaged with first coil member (13712). As will bedescribed in greater detail below, coil members (13712, 13720) areconfigured to cooperatively rigidize articulation section (130).

As can be seen in FIG. 176 first coil member (13712) comprises a firsthelical band (13714) that is wrapped around the exterior of articulationsection (130). First helical band (13714) has a constant helix angle anda constant diameter along the length of articulation section (130).While first helical band (13714) is fixedly secured about articulationsection (130), first helical band (13714) is configured to flex witharticulation section (130) as articulation section (130) articulates.When articulation section (130) articulates, first helical band (13714)flexes such that the helix contracts on one side of the helix axis whilethe helix expands on the other side of the helix axis.

Second coil member (13720) is configured substantially similarly tocomprises first coil member (13712). For instance, second coil member(13720) comprises a second helical band (13722) that is wrapped aroundthe exterior of at least a portion of articulation section (130) and atleast a portion of proximal outer shaft (32). Second helical band(13722) has a constant helix angle and a constant diameter along alength corresponding to the length of articulation section (130). Thehelix angle and diameter of second helical band (13722) is the same asthe helix angle and diameter of first helical band (13714). Moreover,the longitudinal thickness of second helical band (13722) isapproximately the same as the longitudinal spacing between helixsegments of first helical band (13714). Likewise, the longitudinalthickness of first helical band (13714) is approximately the same as thelongitudinal spacing between helix segments of second helical band(13722). It should therefore be understood that the complementaryconfiguration of helical bands (13714, 13722) permits second helicalband (13722) to nest with first helical band (13714). In particular,Therefore, coil members (13712, 13720) are configured such that one coilmember (13712, 13720) is rotatable relative to the other coil member(13712, 13720) to interlock coils (13714, 13722) to thereby form agenerally tubular structure.

Coil members (13712, 13720) comprise a material that is generally rigidwhen coil members (13712, 13720) are interlocked; but is generallybendable when coil members (13712, 13720) are separate. By way ofexample only, suitable materials may include stainless steel, aluminum,or certain polymers such as PTFE, polyethylene terephthalate (PET),high-density polyethylene (HDPE), etc. Of course, any other suitablematerial(s) may be used as will be apparent to those of ordinary skillin the art in view of the teachings herein.

FIGS. 176 and 177 show an exemplary use of sheath assembly (13710).Initially, sheath assembly (13710) may be in a first configuration asshown in FIG. 176. As can be seen, when sheath assembly (13710) is inthe first configuration, coil members (13712, 13720) are longitudinallypositioned such that there is little to no interlocking between eachcoil member (13712, 13720). When coil members (13712, 13720) are in thisarrangement, coil members (13712, 13720) permit free articulation ofarticulation section (130). First coil member (13712) will flex witharticulation section (130) as articulation section (130) articulates.Second coil member (13720) is positioned proximal to articulationsection (130) in this state, such that second coil member (13720) isunaffected by articulation of articulation section (130); and secondcoil member (13720) does not impede articulation of articulation section(130).

If an operator wishes to rigidize actuation section (130), the operatormay transition sheath assembly (13710) to a second configuration shownin FIG. 177. To transition sheath assembly (13710) to the secondconfiguration, the operator may grasp either second coil member (13720)and rotate second coil member (13720) to advance second coil member(13720) distally into engagement with first coil member (13712). Assecond coil member (13720) is rotated, coils (13714, 13722) becomeinterlocked with each other such that coils (13714, 13722) are placed inan alternating relationship. As can be seen in FIG. 177, once the secondconfiguration is reached, coil members (13712, 13720) are fullyinterlocked such that coils (13714, 13722) alternatingly combine to forma rigid tubular structure. With the rigid tubular structure formed, thespacing between each coil (13714, 13722) is eliminated. With the spacingeliminated, the movement of each coil (13714, 13722) is correspondinglylimited such that sheath assembly (13710) forms a rigid structure thatencompasses articulation section (130). Because articulation section(130) is encompassed by the rigid structure of sheath assembly (13710),articulation of articulation section (130) is correspondingly limited.Thus, it should be understood that when sheath assembly (13710) is inthe second position, articulation section (130) is generally lockedand/or rigid.

Although sheath assembly (13710) of the present example is describedherein as being manually actuated by an operator, it should beunderstood that in other examples sheath assembly (13710) may beactuated by other means. For instance, in some examples sheath assembly(13710) may further comprise certain actuation components that are incommunication with articulation bands (140, 142). In examplesincorporating such actuation components, the actuation components areresponsive to movement of articulation bands (140, 142) second coilmember (13720) is automatically transitioned between the first andsecond configurations by movement of articulation bands (140, 142)through certain predetermined positions. Additionally or in thealternative, sheath assembly (13710) may also be spring loaded toautomatically transition second coil member (13720) from the firstconfiguration to the second configuration. As yet another merelyillustrative alternative, sheath assembly (13710) may be actuated byknob (120), some other user input feature at articulation controlassembly (100), and/or some other feature of handle assembly (20). Stillother suitable mechanisms for actuating sheath assembly (13710) will beapparent to those of ordinary skill in the art in view of the teachingsherein.

F. Exemplary Alternative Articulation Section with Rigidizing Linkage

FIGS. 178-179 show a modified version of shaft assembly (30) having alinkage assembly (13810) incorporated therein. Linkage assembly (13810)is generally configured to engage with a portion of articulation section(130) to thereby rigidize articulation section (130). Linkage assembly(13810) comprises a first bar (13820), a second bar (13830), and a thirdbar (13840). As can be seen in FIG. 25 first bar (13820) has a distalend (13822) and a proximal end (13826). Distal end (13822) defines aslot (13824) that is configured to slidably receive a pin (13825). Pin(13825) is fixedly secured to distal outer sheath (33). Pin (13825)connects first bar (13820) to distal outer sheath (33) such that firstbar (13820) is operable to slide a predetermined distance and pivotrelative to distal outer sheath (33). As will be described in greaterdetail below, slot (13824) permits linkage assembly (13810) to sliderelative to shaft assembly (30) to lock and unlock articulation section(130). Proximal end (13826) of first bar (13820) comprises a connector(13828), which pivotably connects first bar (13820) to second bar(13830) as will be described in greater detail below.

Second bar (13830) comprises a distal end (13832) and proximal end(13836). As noted above, second bar (13830) is pivotably secured tofirst bar (13820) via connector (13828). In particular, connector(13828) connects proximal end (13826) of first bar (13820) to distal end(13832) of second bar (13830) such that second bar (13830) is operableto pivot relative to first bar (13820). Proximal end (13836) of secondbar (13830) is pivotably secured to third bar (13840), as will bedescribed in greater detail below.

Third bar (13840) has a distal end (13842) and a proximal end (notshown). Distal end (13842) of third bar (13840) comprises a connector(13844). Connector (13844) is configured to pivotably connect proximalend (13836) of second bar (13830) to distal end of third bar (13840).Accordingly second bar (13830) is configured to pivot relative to thirdbar (13840). Although not shown, it should be understood that theproximal end of third bar (13840) may be connected to an actuator,handle, or other device to provide longitudinal translation of third bar(13840) relative to shaft assembly (30). As will be described in greaterdetail below, such an actuation device permits linkage assembly (13810)to be translated longitudinally relative to shaft assembly (30) toselectively rigidize articulation section (130).

Linkage assembly (13810) further comprises a first pair of ridges(13850) and a second pair of ridges (13852). Each set of ridges (13850,13852) extends upwardly (i.e., out of the page in the views shown inFIGS. 17-179) and longitudinally. First ridges (13850) are fixed to atleast one retention collar (133) (e.g., the middle retention collar(133) in the present example) and are configured to rigidly engageproximal end (13826) of first bar (13820) and distal end (13842) ofsecond bar (13830). In particular, first ridges (13850) receive proximalend (13826) of first bar (13820) and distal end (13842) of second bar(13830) in a gap laterally defined between first ridges (13850). Secondridges (13852) are fixed on at least a portion of proximal outer sheath(32). Second ridges (13852) are configured to rigidly engage proximalend (13836) of second bar (13830) and distal end (13842) of third bar(13840). In particular, second ridges (13852) receive proximal end(13836) of second bar (13830) and distal end (13842) of third bar(13840) in a gap laterally defined between second ridges (13852).Generally, ridges (13850, 13852) are configured to selectively maintainlinkage assembly (13810) in a rigid configuration, as will be describedin greater detail below.

FIGS. 178-179 show an exemplary use of linkage assembly (13810).Initially, linkage assembly (13810) is in a first position as shown inFIG. 178. As can be seen, when linkage assembly (13810) is in the firstposition, bars (13820, 13830, 13840) are positioned such that proximalend (13826) of first bar (13820) and distal end (13832) of second bar(13830) are positioned in the gap laterally defined between first ridges(13850). Additionally, proximal end (13836) of second bar (13830) anddistal end (13842) of third bar (13840) are positioned in the gaplaterally defined between second ridges (13852). Because of thispositioning, ridges (13850, 13852) maintain linkage assembly (13810) ina rigid position. Additionally, because first ridges (13850) are securedto at least one retention collar (133), articulation section (130) isalso maintained in a rigid configuration. Therefore, when linkageassembly (13810) is in the first position, linkage assembly (13810)rigidizes articulation section (130).

If an operator desires to articulate articulation section (130), theoperator may transition linkage assembly (13810) to a second positionshown in FIG. 179. To transition linkage assembly (13810) to the secondposition, an operator may actuate third bar (13840) proximally tolongitudinally translate linkage assembly (13810) proximally.Alternatively, if instrument (10) is so equipped, an operator mayactuate articulation control assembly (100) or other device describedabove that may be connected to the proximal end of third bar (13840).Regardless of how linkage assembly (13810) is longitudinally translatedproximally, it should be understood that such translation will lead tobars (13820, 13830, 13840) becoming disengaged from ridges (13850,13852). In particular, as linkage assembly (13810) is translatedproximally, bars (13820, 13830, 13840) may deflect upwardly (i.e., outof the page in the views shown in FIGS. 178-179) to exit the gapslaterally defined between ridges (13850, 13852) such that bars (13820,13830, 13840) become free to move transversely relative to ridges(13850, 13852). With bars (13820, 13830, 13840) free from ridges (13850,13852), bars (13820, 13830, 13840) are now operable to pivot about pin(13825) and connectors (13828, 13844). Thus, linkage assembly (13810) isno longer in a rigid state. Because linkage assembly (13810) is not in arigid state and because linkage assembly is no longer engaged with slot(13850), linkage assembly (13810) no longer rigidizes articulationsection (130).

G. Exemplary Alternative Articulation Section with TranslatableRigidizing Member

FIGS. 180-182 show a modified version of shaft assembly (30) equippedwith a rigidizing plate assembly (13910). Plate assembly (13910)comprises a rigidizing member (13920), an actuation assembly (13920),and a pair of plate tracks (13940) secured to each retention collar(133) of articulation section (130). Rigidizing member (13920) isgenerally configured to translate longitudinally across the upperportion of proximal outer sheath (32) and articulation section (130) toselectively rigidize articulation section (130). As can be seen in FIG.28, rigidizing member (13920) is has a generally rectangular shape thatis contoured to correspond to the outer radius of proximal outer sheath(32). Rigidizing member (13920) further comprises two L-shapedengagement members (13922, 13924). Rigidizing member (13920) is formedof a rigid material such as plastic, metal, and/or any other suitablerigid material(s). As will be described in greater detail below,engagement members (13922, 13924) are generally configured to engage andslide along plate tracks (13940) rigidize articulation section (130).

Actuation assembly (13920) further comprises a pair of distal wires(13932) and a pair of proximal wires (13934). Each pair of wires (13932,13934) is secured to rigidizing member (13920) such that wires (13932,13934) are configured to pull rigidizing member (13920) distally orproximally. Distal wires (13932) extend distally and are received in apair of openings (936) in distal outer sheath (33). Openings (936) maybe connected to a pair of passages extending through shaft assembly (30)to thereby permit distal wires (13932) to return to handle assembly (20)described above. Similarly, proximal wires (13934) extend proximallydown the length of shaft assembly (30) until proximal wires (13934) maybe received by handle assembly (20). Although not shown, it should beunderstood that actuation assembly (13920) may include features disposedin handle assembly (20) for actuating wires. By way of example only,such features may include a rotatable wheel, which may drive wires(13932, 13934) to thereby translate rigidizing member (13920) proximallyor distally. Of course, any other suitable features for driving wires(13932, 13934) may be incorporated into instrument (10) as will beapparent to those of ordinary skill in the art in view of the teachingsherein. Similarly, wires (13932, 13934) are just one merely illustrativeexample of how rigidizing member (13920) may be driven between aproximal position and a distal position. Other suitable features thatmay be used to drive rigidizing member (13920) between a proximalposition and a distal position will be apparent to those of ordinaryskill in the art in view of the teachings herein.

Tracks (13940) are fixedly secured to each retention collar (133).Tracks (13940) are generally shaped to slidably receive the L-shape ofengagement members (13922, 13924). In other words, tracks (13940) areconfigured such that engagement members (13922, 13924) are permitted toslide longitudinally within tracks (13940), while limiting any lateralmovement of engagement members (13922, 13924). Although tracks (13940)are described herein as being secured to each retention collar (133), itshould be understood that in other examples, tracks (13940) may beunitarily formed features of retention collars (133).

An exemplary use of plate assembly (13910) can be seen in FIGS. 180 and182. As can be seen in FIG. 180, plate assembly (13910) is initially ina first longitudinal position. In the first position, rigidizing member(13920) is disposed proximally of articulation section (130). Becauserigidizing member (13920) is disposed proximally of articulation section(130), rigidizing member (13920) is not acting upon actuation section(130) and articulation section (130) is thus free to articulate.Therefore, when plate assembly (13910) is in the first position,articulation section (130) is unlocked and/or otherwise free toarticulate via articulation control assembly (100) described above.

If an operator desires to rigidize articulation section (130), theoperator may transition plate assembly (13910) to a second longitudinalposition shown in FIG. 182. In the second position, rigidizing member(13920) is in a distal position such that rigidizing member (13920) isin engagement with articulation section (130). To transition rigidizingmember (13920) to the second position, the operator may actuate wires(13932, 13934) of actuation assembly (13920) to pull rigidizing member(13920) distally using any of the above described mechanisms. Asrigidizing member (13920) moves distally, engagement members (13922,13924) of rigidizing member (13920) will be slidably received by tracks(13920) until rigidizing member (13920) is disposed at the distalposition. In the distal position, engagement members (13922, 13924) ofrigidizing member (13920) remain disposed within tracks (13940). Becauseengagement members (13922, 13924) are integral to rigidizing member(13920), the rigidity of rigidizing member (13920) is imparted ontoengagement members (13922, 13924). Because engagement members (13922,13924) engage tracks (13940) that are fixedly secured to retentioncollars (133), the rigidity of rigidizing member (13920) is imparted toretention collars (133) and articulation section (130). Therefore, plateassembly (13910) rigidizes articulation section (130) when plateassembly (13910) is in the second position. If the operator wishes toarticulate articulation section (130), the operator may simply retractrigidizing member (13920) proximally back to the first position shown inFIG. 180, thereby de-rigidizing articulation section (130) and enablingarticulation section (130) to flex in response to actuation ofarticulation control assembly (100).

H. Exemplary Alternative Instrument with Translatable Outer Sheath

FIG. 183 shows an exemplary alternative instrument (131010). Instrument(131010) of the present example is substantially the same as instrument(10) described above, except as otherwise noted herein. For instance,instrument (131010) of the present example comprises a handle assembly(131020), a shaft assembly (131030), and an end effector (131040).Handle assembly (131020) comprises a body (131022) including a pistolgrip (131024) and a pair of buttons (131026). Handle assembly (131020)also includes a trigger (131028) that is pivotable toward and away frompistol grip (131024). It should be understood, however, that variousother suitable configurations may be used, including but not limited toa scissor grip configuration. End effector (131040) includes anultrasonic blade (131160) and a pivoting clamp arm (131044). Clamp arm(131044) is coupled with trigger (131028) such that clamp arm (131044)is pivotable toward ultrasonic blade (131160) in response to pivoting oftrigger (131028) toward pistol grip (131024); and such that clamp arm(131044) is pivotable away from ultrasonic blade (131160) in response topivoting of trigger (131028) away from pistol grip (131024). Varioussuitable ways in which clamp arm (131044) may be coupled with trigger(131028) will be apparent to those of ordinary skill in the art in viewof the teachings herein. In some versions, one or more resilient membersare used to bias clamp arm (131044) and/or trigger (131028) to the openposition shown in FIG. 183.

An ultrasonic transducer assembly (131012) extends proximally from body(131022) of handle assembly (131020). Transducer assembly (131012) iscoupled with a generator (131016) via a cable (131014), such thattransducer assembly (131012) receives electrical power from generator(131016). Piezoelectric elements in transducer assembly (131012) convertthat electrical power into ultrasonic vibrations. Generator (131016) mayinclude a power source and control module that is configured to providea power profile to transducer assembly (131012) that is particularlysuited for the generation of ultrasonic vibrations through transducerassembly (131012).

Blade (131160) of the present example is operable to vibrate atultrasonic frequencies in order to effectively cut through and sealtissue. Blade (131160) is positioned at the distal end of an acousticdrivetrain. This acoustic drivetrain includes transducer assembly(131012) and an acoustic waveguide (not shown). The acoustic waveguidecomprises a flexible portion (not shown) similar to flexible portion(166) described above with respect to instrument (10). Transducerassembly (131012) includes a set of piezoelectric discs (not shown)located proximal to a horn (not shown) of the waveguide. Thepiezoelectric discs are operable to convert electrical power intoultrasonic vibrations, which are then transmitted along the waveguide toblade (131160) in accordance with known configurations and techniques.By way of example only, this portion of the acoustic drivetrain may beconfigured in accordance with various teachings of various referencesthat are cited herein.

Shaft assembly (131030) of the present example extends distally fromhandle assembly (131020). Unless otherwise noted herein, shaft assembly(131030) is substantially the same as shaft assembly (30) describedabove with respect to instrument (10). For instance, shaft assembly(131030) includes an articulation section (131130), which is located ata distal portion of shaft assembly (131030), with end effector (131040)being located distal to articulation section (131130). As shown in FIG.183, a knob (131031) is secured to a proximal portion of shaft assembly(131030). Knob (131031) is rotatable relative to body (131022), suchthat shaft assembly (131030) is rotatable about the longitudinal axisdefined by shaft assembly (131030), relative to handle assembly(131020). Such rotation may provide rotation of end effector (131040),articulation section (131130), and shaft assembly (131030) unitarily. Ofcourse, rotatable features may simply be omitted if desired.

Articulation section (131130) is substantially the same as articulationsection (130) described above with respect to instrument (10), unlessotherwise note herein. For instance, articulation section (131130) isoperable to selectively position end effector (131040) at variouslateral deflection angles relative to a longitudinal axis defined byshaft assembly (131030). Like with articulation section (130),articulation section (131130) is driven by a pair of articulation bands(not shown) disposed within articulation section (131130) and extendingthrough shaft assembly (131030). When the articulation bands translatelongitudinally in an opposing fashion, this will cause articulationsection (131130) to bend, thereby laterally deflecting end effector(131040) away from the longitudinal axis of shaft assembly (131030) froma straight configuration to an articulated configuration. In particular,end effector (131040) will be articulated toward the articulation bandthat is being pulled proximally. During such articulation, the otherarticulation band may be pulled distally.

Instrument (131100) further includes an articulation control assembly(131100) that is secured to a proximal portion of shaft assembly(131030). Articulation control assembly (131100) comprises a housing(131110) and a rotatable knob (131120). Like with articulation controlassembly (100) described above, rotatable knob (131120) is configured torotate relative to housing (131110) to drive the articulation bands inopposing directions.

Unlike instrument (10) described above, instrument (131010) of thepresent example further includes a sheath drive assembly (131200).Sheath drive assembly (131200) is generally operable to translate aproximal outer sheath (131032) of shaft assembly (131030) to lock and/orincrease the rigidity of articulation section (131130). Sheath driveassembly (131200) comprises an actuation driver (131210) extendingthrough a slot (131220) disposed on the exterior of handle assembly(131020).

FIG. 31 shows an exploded view of outer sheath (131032) and actuationdriver (131210). As can be seen, outer sheath (131032) comprises a pairof flanges (131034) and a slot (131036). Flange pair (131034) isdisposed at the proximal end of outer sheath (131032) and is configuredto receive a corresponding portion of actuation driver (131210), as willbe described in greater detail below. Slot (131036) is disposed in outersheath (131032) proximally of the distal end of outer sheath (131032).Slot (131036) is configured to permit components associated withrotatable knob (131031) to extend through outer sheath (131032) suchthat outer sheath (131032) and other components of shaft assembly(131030) may be rotated by rotatable knob (131031).

Actuation driver (131210) is shown in FIG. 185. As can be seen,actuation driver (131210) comprises an annular member (131212), twoarmatures (131214), and two tabs (131216) Annular member (131212) isconfigured to be rotatably received by flange pair (131034) of outersheath (131032). When annular member (131212) is disposed betweenflanges (131034), outer sheath (131032) can freely rotate relative toannular member (131212). This feature may be desirable because freerotation of outer sheath (131032) relative to annular member (131212)may permit outer sheath (131032) to rotate while actuation driver(131210) may remain fixed. This feature may be further desirable becauseflange pair (131034) may still permit actuation driver (131210) to drivetranslation of outer sheath (131032) despite rotation of outer sheath(131032).

Armatures (131214) extend outwardly from annular member (131212).Armatures (131214) are configured to extend through corresponding slots(131220) in handle assembly (131020), with each tab (131216) disposed onthe exterior of handle assembly (131020). Thus, armatures (131214)connect tabs (131216), which are disposed on the outside of handleassembly (131020), to annular member (131212), which is disposed on theinside of handle assembly (131020).

FIGS. 183 and 186 show an exemplary use of sheath drive assembly(131200). As can be seen in FIG. 183, sheath drive assembly (131200) isinitially in a first longitudinal position. In the first position, outersheath (131032) is disposed in a proximal position such that outersheath (131032) is proximal of articulation section (131130).Correspondingly, actuation driver (131210) is in a proximal positionrelative to slot (131220). Thus, in the first position, articulationsection (131130) is free to articulate via articulation control assembly(131100) as described above.

If an operator desires to rigidize articulation section (131130), theoperator may actuate sheath drive assembly (131200) to a secondlongitudinal position shown in FIG. 186. In the second position, outersheath (131032) is driven distally over articulation section (131130).To drive outer sheath (131032) distally to the distal position shown inFIG. 186, the operator may apply a force distally to tab (131216) ofactuation driver (131210) thereby driving actuation driver (131210)distally. Actuation driver (131210) will then act on flange (131034) ofouter sheath (131032) via annular member (131212) to drive outer sheath(131032) distally. Once outer sheath (131032) is disposed overarticulation section (131130), the rigidity of outer sheath (131032)will rigidize articulation section (131130). Therefore, it should beunderstood that when sheath drive assembly (131200) is in the secondposition, articulation section (131130) is rigidized.

In some versions, one or more features in communication with actuationdriver (131210) will also lock out rotatable knob (131120) such thatknob (131120) cannot be rotated when actuation driver (131210) is in thedistal position. In addition or in the alternative, one or more featuresin communication with knob (131120) may lock out actuation driver(131210) such that actuation driver (131210) cannot be slid from theproximal position to the distal position unless knob (131120) is at theneutral rotational position that is associated with articulation section(131130) being in a straight, non-articulated configuration. Varioussuitable ways in which such lockout features may be configured will beapparent to those of ordinary skill in the art in view of the teachingsherein.

As yet another merely illustrative example, one or more features incommunication with actuation driver (131210) may be configured toautomatically de-articulate an otherwise articulated articulationsection (131130) in response to distal movement of actuation driver(131210) from the proximal position toward the distal position. Varioussuitable ways in which such features may be configured will be apparentto those of ordinary skill in the art in view of the teachings herein.

I. Exemplary Alternative Instrument with Translatable Rigidizing Members

FIG. 187 shows an exemplary alternative instrument (131310). Instrument(131310) of the present example is substantially the same as instrument(10) described above, except as otherwise noted herein. For instance,instrument (131310) of the present example comprises a handle assembly(131320), a shaft assembly (131330), and an end effector (131340).Handle assembly (131320) comprises a body (131322) including a pistolgrip (131324) and a pair of buttons (131326). Handle assembly (131320)also includes a trigger (131328) that is pivotable toward and away frompistol grip (131324). It should be understood, however, that variousother suitable configurations may be used, including but not limited toa scissor grip configuration. End effector (131340) includes anultrasonic blade (131460) and a pivoting clamp arm (131344). Clamp arm(131344) is coupled with trigger (131328) such that clamp arm (131344)is pivotable toward ultrasonic blade (131460) in response to pivoting oftrigger (131328) toward pistol grip (131324); and such that clamp arm(131344) is pivotable away from ultrasonic blade (131460) in response topivoting of trigger (131328) away from pistol grip (131324). Varioussuitable ways in which clamp arm (131344) may be coupled with trigger(131328) will be apparent to those of ordinary skill in the art in viewof the teachings herein. In some versions, one or more resilient membersare used to bias clamp arm (131344) and/or trigger (131328) to the openposition shown in FIG. 187.

An ultrasonic transducer assembly (131312) extends proximally from body(131322) of handle assembly (131320). Transducer assembly (131312) iscoupled with a generator (131316) via a cable (131314), such thattransducer assembly (131312) receives electrical power from generator(131316). Piezoelectric elements in transducer assembly (131312) convertthat electrical power into ultrasonic vibrations. Generator (131316) mayinclude a power source and control module that is configured to providea power profile to transducer assembly (131312) that is particularlysuited for the generation of ultrasonic vibrations through transducerassembly (131312).

Blade (131460) of the present example is operable to vibrate atultrasonic frequencies in order to effectively cut through and sealtissue. Blade (131460) is positioned at the distal end of an acousticdrivetrain. This acoustic drivetrain includes transducer assembly(131312) and an acoustic waveguide (131480) (as can be seen in FIG.190). The acoustic waveguide (131480) comprises a flexible portion (notshown) similar to flexible portion (166) described above with respect toinstrument (10). Transducer assembly (131312) includes a set ofpiezoelectric discs (not shown) located proximal to a horn (not shown)of waveguide (131480). The piezoelectric discs are operable to convertelectrical power into ultrasonic vibrations, which are then transmittedalong waveguide (131480) to blade (131460) in accordance with knownconfigurations and techniques. By way of example only, this portion ofthe acoustic drivetrain may be configured in accordance with variousteachings of various references that are cited herein.

Shaft assembly (131330) of the present example extends distally fromhandle assembly (131320). Unless otherwise noted herein, shaft assembly(131330) is substantially the same as shaft assembly (30) describedabove with respect to instrument (10). For instance, shaft assembly(131330) includes an articulation section (131430), which is located ata distal portion of shaft assembly (131330), with end effector (131340)being located distal to articulation section (131430). As shown in FIG.187, a knob (131331) is secured to a proximal portion of shaft assembly(131330). Knob (131331) is rotatable relative to body (131322), suchthat shaft assembly (131330) is rotatable about the longitudinal axisdefined by shaft assembly (131330), relative to handle assembly(131320). Such rotation may provide rotation of end effector (131340),articulation section (131430), and shaft assembly (131330) unitarily. Ofcourse, rotatable features may simply be omitted if desired.

Articulation section (131430) is substantially the same as articulationsection (130) described above with respect to instrument (10), unlessotherwise note herein. For instance, articulation section (131430) isoperable to selectively position end effector (131340) at variouslateral deflection angles relative to a longitudinal axis defined byshaft assembly (131430). Like with articulation section (130),articulation section (131430) is driven by a pair of articulation bands(131440, 131442) (as shown in FIG. 190) disposed within articulationsection (131430) and extending through shaft assembly (131330). Whenarticulation bands (131440, 131442) translate longitudinally in anopposing fashion, this will cause articulation section (131430) to bend,thereby laterally deflecting end effector (131340) away from thelongitudinal axis of shaft assembly (131330) from a straightconfiguration to an articulated configuration. In particular, endeffector (131340) will be articulated toward the articulation band(131440, 131442) that is being pulled proximally. During sucharticulation, the other articulation band (131440, 131442) may be pulleddistally

Instrument (131310) further includes an articulation control assembly(131400) that is secured to a proximal portion of shaft assembly(131330). Articulation control assembly (131400) comprises a housing(131410) and a rotatable knob (131420). Like with articulation controlassembly (100) described above, rotatable knob (131420) is configured torotate relative to housing (131410) to drive articulation bands (131440,131442) in opposing directions. For instance, rotation of knob (131420)in a first direction causes distal longitudinal translation ofarticulation band (131440), and proximal longitudinal translation ofarticulation band (131442); and rotation of knob (131420) in a seconddirection causes proximal longitudinal translation of articulation band(131440), and distal longitudinal translation of articulation band(131442). Thus, it should be understood that rotation of rotation knob(131420) causes articulation of articulation section (131430).

Unlike instrument (10) described above, instrument (131310) of thepresent example further includes a rigidizing member drive assembly(131500). Drive assembly (131500) is generally operable to advance arigidizing member (131520) within shaft assembly (131330) selectivelyrigidize articulation section (131430). Drive assembly (131500)comprises drive member (131510) and a rigidizing member (131520). Drivemember (131510) extends through a slot (131530) in handle assembly(131320) and is rotatably attachable to rigidizing member (131520) todrive rigidizing member (131520) while permitting rotation of rigidizingmember (131520) with shaft assembly (131330).

As can be seen in FIG. 188, rigidizing member (131520) comprises twolongitudinally extending posts (131522) and a generally tubular body(131524). As will be described in greater detail below, posts (131522)extend through shaft assembly (131330) and engage with articulationsection (131430) to selectively ridigize articulation section (131430).Body (131524) comprises a flange pair (131526) and a slot (131528).Flange pair (131526) is disposed on the proximal end of body (131524)and is configured to receive drive member (131510), as will be describedin greater detail below. Slot (131528) is disposed distally of flangepair (131526). Slot (131528) is configured to receive at least a portionof rotatable knob (131331) such that rotatable knob (131331) may engagewith rigidizing member (131520) and various components of shaft assembly(131330) to rotate rigidizing member (131520) along with shaft assembly(131330).

Drive member (131510) is shown in FIG. 189. As can be seen, drive member(131510) comprises an annular member (131512), two armatures (131514),and two tabs (131516). Annular member (131512) is configured to berotatably received by flanged portion (131526) of rigidizing member(131520). When annular member (131512) is between flanges (131526),rigidizing member (131520) can freely rotate relative to annular member(131512). This feature may be desirable because free rotation ofrigidizing member (131520) relative to annular member (131512) maypermit rigidizing member (131520) to rotate while drive member (131510)may remain fixed. This feature may be further desirable because flangepair (131526) may still permit drive member (131510) to drivetranslation of rigidizing member (131520) despite rotation of rigidizingmember (131520).

Armatures (131514) extend outwardly from annular member (131512).Armatures (131514) are configured to extend through corresponding slots(131530) in handle assembly (131320), with each tab (131516) disposed onthe exterior of handle assembly (131320). Thus, armatures (131514)connect tabs (131516), which are disposed on the outside of handleassembly (131320), to annular member (131512), which is disposed on theinside of handle assembly (131320).

FIG. 190 shows rigidizing member (131520) disposed within shaft assembly(131330). As can be seen, a body (131334) of shaft assembly (131330)includes channels (131336) that are configured to receive botharticulation bands (131440, 131442) and posts (131522) of rigidizingmember (131520) adjacent to articulation bands (131440, 131442).Although shaft assembly (131330) of the present example is shown ashaving a common channels (131336) for both articulation bands (131440,131442) and posts (131522), it should be understood that in otherexamples, shaft assembly (131330) includes separate channels forarticulation bands (131440, 131442) and posts (131522).

FIGS. 191-196 show an exemplary mode of operation for drive assembly(131500). As can be seen in FIGS. 191-192, drive assembly (131500) isinitially in a first longitudinal position. In the first position, drivemember (131510) is positioned in a proximal position relative to handleassembly (131320) such that rigidizing member (131520) iscorrespondingly in a proximal position relative to articulation section(131430). As can best be seen in FIG. 192, when rigidizing member(131520) is in the proximal position, posts (131522) of rigidizingmember (131520) are disposed proximally of articulation section(131430). With posts (131522) of rigidizing member (131520) disposedproximally of articulation section (131430), articulation section(131430) is free to articulate via articulation control assembly(131400) as described above. Thus, when drive assembly (131500) is inthe first position, articulation section (131430) is in an unlockedand/or non-rigid configuration.

If an operator desires to rigidize articulation section (131430), theoperator may do so by advancing drive assembly (131500) to a secondlongitudinal position (as shown in FIGS. 195-196). To advance driveassembly (131500) to the second position, the operator will advance tabs(131516) of drive member (131510) distally as shown in FIG. 193. Distaladvancement of drive member (131510) will cause correspondingadvancement of posts (131522) of rigidizing member (131520) within shaftassembly (131330) as shown in FIG. 194. As posts (131522) are advanceddistally, posts (131522) begin to engage articulation section (131430).FIGS. 195-196 show drive assembly (131500) fully advanced to the secondposition. As can be seen, in the second position, tabs (131516) of drivemember (131510) are advanced to a fully distal position relative tohandle assembly (131320). Correspondingly, posts (131522) of rigidizingmember (131520) are advanced to a fully distal position. When posts(131522) are in the fully distal position, posts (131522) fully engagearticulation section (131430) to rigidize articulation section (131430).In this state, the distal ends of posts (131522) are positioned distalto articulation section (131430), such that posts (131522) span alongthe full length of articulation section (131430) and are groundedrelative to the distal portion of shaft assembly (131330).

In some examples, instrument (131310) described above may include arigidizing member drive assembly similar to drive assembly (131600)described above having a rigidizing member (131620) with a single post(131622). Such a configuration may be desirable to improve the overalloperation of instrument (131310), to improve the ease of use, or toimprove the amount of rigidity provided by rigidizing member (131520).For instance, FIGS. 197-199 show an exemplary alternative rigidizingmember drive assembly (131600). It should be understood that driveassembly (131600) is substantially the same as drive assembly (131500)described above, unless otherwise noted herein. Drive assembly (131600)of the present example is generally operable to advance a rigidizingmember (131620) within shaft assembly (131330) to selectively rigidizearticulation section (131430). Drive assembly (131600) comprises drivemember (131610) and rigidizing member (131620). Drive member (131610)extends through a slot (131630) in handle assembly (131320) and isrotatably attached to rigidizing member (131620) to drive rigidizingmember (131620) while permitting rotation of rigidizing member (131620)with shaft assembly (131330).

As can be seen in FIG. 197, rigidizing member (131620) comprises asingle longitudinally extending post (131622) and a generally tubularbody (131624). As will be described in greater detail below, post(131622) extends through shaft assembly (131330) and engages witharticulation section (131430) to selectively rigidize articulationsection (131430). Body (131624) comprises a flange pair (131626) and aslot (131628). Flange pair (131626) is disposed on the proximal end ofbody (131624) and is configured to receive drive member (131610), aswill be described in greater detail below. Slot (131628) is disposeddistally of flanged portion (131626). Slot (131628) is configured toreceive at least a portion of rotatable knob (131331) such thatrotatable knob (131331) may engage with rigidizing member (131620) andvarious components of shaft assembly (131330) to rotate rigidizingmember (131620) along with shaft assembly (131330).

Drive member (131610) is shown in FIG. 198. As can be seen, drive member(131610) comprises an annular member (131612), two armatures (131614),and two tabs (131616) Annular member (131612) is configured to berotatably received between flanges (131626) of rigidizing member(131620). When annular member (131612) is disposed between flanges(131626), rigidizing member (131620) can freely rotate relative toannular member (131612). This feature may be desirable because freerotation of rigidizing member (131620) relative to annular member(131612) may permit rigidizing member (131620) to rotate while drivemember (131610) may remain fixed. This feature may be further desirablebecause flange pair (131626) may still permit drive member (131610) todrive translation of rigidizing member (131620) despite rotation ofrigidizing member (131620).

Armatures (131614) extend outwardly from annular member (131612).Armatures (131614) are configured to extend through slot (131630) inhandle assembly (131320) with each tab (131616) disposed on the exteriorof handle assembly (131320). Thus, armatures (131614) connect tabs(131616), which are disposed on the outside of handle assembly (131320),to annular member (131612), which is disposed on the inside of handleassembly (131320).

FIG. 199 shows rigidizing member (131620) disposed within shaft assembly(131330). As can be seen, a body (131334) of shaft assembly includeschannels (131336) that are configured to receive articulation bands(131440, 131442). Additionally body (131334) includes an additionalchannel (131338) to receive post (131622) of rigidizing member (131620).

FIGS. 200-205 show an exemplary mode of operation for drive assembly(131600). As can be seen in FIGS. 200-201, drive assembly (131600) isinitially in a first longitudinal position. In the first position, drivemember (131610) is positioned in a proximal position relative to handleassembly (131320) such that rigidizing member (131620) iscorrespondingly in a proximal position. As can best be seen in FIG. 201,when rigidizing member (131620) is in the proximal position, post(131622) of rigidizing member (131620) is disposed proximally ofarticulation section (131430). With post (131622) of rigidizing member(131620) disposed proximally of articulation section (131430),articulation section (131430) is free to articulate via articulationcontrol assembly (131400) as described above. Thus, when drive assembly(131600) is in the first position, articulation section (131430) is inan unlocked and/or non-rigid configuration.

If an operator desires to rigidize articulation section (131430), theoperator may do so by advancing drive assembly (131600) to a secondlongitudinal position (as shown in FIGS. 204-205). To advance driveassembly (131600) to the second position, the operator will advance tabs(131616) of drive member (131610) distally as shown in FIG. 202. Distaladvancement of drive member (131610) will cause correspondingadvancement of post (131622) of rigidizing member (131620) within shaftassembly (131330) as shown in FIG. 203. As post (131622) is advanceddistally, post (131622) begins to engage articulation section (131430).

FIGS. 204-205 show drive assembly (131600) fully advanced to the secondposition. As can be seen, in the second position, tabs (131616) of drivemember (131610) are advanced to a fully distal position relative tohandle assembly (131320). Correspondingly, post (131622) of rigidizingmember (131520) is advanced to a fully distal position. When post(131622) is in the fully distal position, post (131622) fully engagesarticulation section (131430) to rigidize articulation section (131430).In this state, the distal ends of post (131622) is positioned distal toarticulation section (131430), such that post (131622) spans along thefull length of articulation section (131430) and is grounded relative tothe distal portion of shaft assembly (131330). In the present example,post (131622) extends along a path that is offset from the articulationplane of articulation section (131430). In particular, post (131622) islocated above the articulation plane of articulation section (131430).This positioning of post (131622) may enhance the rigidization effectprovided by post (131622) when post (131622) is in the distal positionshown in FIG. 205. In some other versions, post (131622) is located inthe articulation plane of articulation section (131430) (e.g., similarto the positioning of one of posts (131522)), on one side ofarticulation section (131430).

XV. ULTRASONIC SURGICAL INSTRUMENT WITH ARTICULATING END EFFECTOR HAVINGA CURVED BLADE

FIGS. 206-208 show an exemplary alternative waveguide (14280) that maybe readily incorporated into instrument (10), particularly, into anacoustic drivetrain of instrument (10). Waveguide (14280) of the presentexample includes a blade (14260), which is operable to vibrate atultrasonic frequencies in order to effectively cut through and sealtissue, particularly when the tissue is being compressed between blade(14260) and another portion of an end effector, such as a curved versionof clamp pad (46) of end effector (40). As best shown in FIG. 208, blade(14260) is curved at a bend angle “0” relative to a longitudinal axis ofwaveguide (14280).

In one example, the acoustic drivetrain includes transducer assembly(12) and acoustic waveguide (14280). Acoustic waveguide (14280)comprises a flexible portion (14266). Transducer assembly (12) includesa set of piezoelectric discs (not shown) located proximal to a horn (notshown) of waveguide (14280). The piezoelectric discs are operable toconvert electrical power into ultrasonic vibrations, which are thentransmitted along waveguide (14280), including flexible portion (14266)of waveguide (14280), to blade (14260) in accordance with knownconfigurations and techniques. By way of example only, this portion ofthe acoustic drivetrain may be configured in accordance with variousteachings of various references that are cited herein.

Flexible portion (14266) of waveguide (14280) includes a distal flange(14236), a proximal flange (14238), and a narrowed section (14264)located between flanges (14236, 14238). Waveguide (14280) includeslongitudinally extending notches that are formed in the waveguideflanges to accommodate cable (14274), which is discussed in more detailbelow. Cable is received in the lower notches (not shown); and the uppernotches (14237, 14239) are formed to provide balance (i.e., tocompensate for the presence of the lower notches). Waveguide (14280)includes a tapered region (14239) between distal flange (14236) andblade (14260). In the present example, flanges (14236, 14238) arelocated at positions corresponding to nodes associated with resonantultrasonic vibrations communicated through waveguide (14280). Narrowedsection (14264) is configured to allow flexible portion (14266) ofwaveguide (14280) to flex without significantly affecting the ability offlexible portion (14266) of waveguide (14280) to transmit ultrasonicvibrations. By way of example only, narrowed section (14264) may beconfigured in accordance with one or more teachings of U.S. Pub. No.2014/0005701, issued as U.S. Pat. No. 9,393,037 on Jul. 19, 2016, and/orU.S. Pub. No. 2014/0114334, issued as U.S. Pat. No. 9,095,367 on Aug. 4,2015, the disclosures of which are incorporated by reference herein.

It should be understood that waveguide (14280) may be configured toamplify mechanical vibrations transmitted through waveguide (14280).Furthermore, waveguide (14280) may include features operable to controlthe gain of the longitudinal vibrations along waveguide (14280) and/orfeatures to tune waveguide (14280) to the resonant frequency of thesystem. For example, as shown in FIG. 206, waveguide (14280) includes aplurality of opposing pairs of longitudinally spaced, laterallypresented notches (14282 a, 14282 b). In the present example, each notch(14282 a) of the three most proximal pairs of notches (14282 a) has alonger length than each notch (14282 b) of the two most distal pairs ofnotches (14282 b). Notches (14282 a, 282 b) are provided, at least inpart, to assist in controlling the vibratory properties of the waveguide(14280), which are different in waveguide (14280) than in waveguide(180) due in part to the curved configuration of blade (14260). Varioussuitable ways in which waveguide (14280) may be mechanically andacoustically coupled with transducer assembly (12) will be apparent tothose of ordinary skill in the art in view of the teachings herein.

Each flange (14236, 14238) of waveguide (14280) includes a respectivepair of opposing, laterally presented flats (14292, 14296). Flats(14292, 14296) are oriented along vertical planes that are parallel to avertical plane extending through narrowed section (14264) of flexibleportion (14266). Flats (14296) are configured to provide clearance forarticulation bands (14212, 14214). In particular, flats (14296) ofproximal flange (14238) accommodate articulation bands (14214) betweenproximal flange (14238) and the inner diameter of proximal outer sheath(14204). Notably, articulation bands (14212, 14214) are coupled towaveguide (14280) at a point proximal to distal flange (14236). Ofcourse, flats (14292, 14296) could be substituted with a variety offeatures, including but not limited to slots, channels, etc., with anysuitable kind of profile (e.g., square, flat, round, etc.). In thepresent example, flats (14292, 14296) are formed in a milling process,though it should be understood that any other suitable process(es) maybe used. Various suitable alternative configurations and methods offorming flats (14292, 14296) will be apparent to those of ordinary skillin the art in view of the teachings herein. It should also be understoodthat waveguide (14280) may include flats formed in accordance with atleast some of the teachings of U.S. Pub. No. 2013/0289592, entitled“Ultrasonic Device for Cutting and Coagulating,” published Oct. 31,2013, the disclosure of which is incorporated by reference herein.

In the present example, the distal end of blade (14260) is located at aposition corresponding to an anti-node associated with resonantultrasonic vibrations communicated through flexible portion (14266) ofwaveguide (14280), in order to tune the acoustic assembly to a preferredresonant frequency f_(o) when the acoustic assembly is not loaded bytissue. When transducer assembly (12) is energized, the distal end ofblade (14260) is configured to move longitudinally in the range of, forexample, approximately 10 to 500 microns peak-to-peak, and in someinstances in the range of about 20 to about 200 microns at apredetermined vibratory frequency f_(o) of, for example, 55.5 kHz. Whentransducer assembly (12) of the present example is activated, thesemechanical oscillations are transmitted through waveguide (14280) toreach blade (14260), thereby providing oscillation of blade (14260) atthe resonant ultrasonic frequency. Thus, when tissue is secured betweenblade (14260) and a curved version of clamp pad (46), for example, theultrasonic oscillation of blade (14260) may simultaneously sever thetissue and denature the proteins in adjacent tissue cells, therebyproviding a coagulative effect with relatively little thermal spread. Insome versions, an electrical current may also be provided through blade(14260) and clamp arm (44) to also cauterize the tissue. While someconfigurations for an acoustic transmission assembly and transducerassembly (12) have been described, still other suitable configurationsfor an acoustic transmission assembly and transducer assembly (12) willbe apparent to one or ordinary skill in the art in view of the teachingsherein. Similarly, various suitable ways in which waveguide (14280) maybe configured will be apparent to those of ordinary skill in the art inview of the teachings herein.

FIGS. 209-211 and 227A-228B show an exemplary alternative shaft assembly(14200) and end effector (14240) that may be readily incorporated intoinstrument (10). In the example shown, shaft assembly (14200) and endeffector are configured to accommodate for the properties of curvedblade (14260), as discussed in more detail below. Shaft assembly (14200)of this example comprises a distal outer sheath (14202), a proximalouter sheath (14204), and a plurality of flex rings (14206) that form aportion of an articulation section (14210). While articulation section(130) is configured to articulate in two lateral directions relative tothe longitudinal axis of shaft assembly (30), articulation section(14210) of the present example is configured to articulate in only onedirection relative to a longitudinal axis of shaft assembly (14200).Particularly, in the present example, articulation section (14210) isallowed to articulate in one lateral direction, but is substantiallyprevented from articulating in the opposite lateral direction.

Articulation section (14210) is operable to selectively position endeffector (14240) at various lateral deflection angles, in one direction,relative to a longitudinal axis defined by proximal outer sheath(14204). In the present example, the direction in which articulationsection (14210) is permitted to articulate is the same direction whichcurved blade (14260) bends away from the axis (at bend angle (A)). Endeffector (14240) includes blade (14260) and a pivoting clamp arm (14244)having a clamp pad (14245). In the present example, clamp arm (14244)and clamp pad (14245) are curved at a bend angle that is substantiallysimilar to the bend angle (A) of blade (14260). End effector (14240) isconfigured to operate substantially similar to end effector (40)discussed above except for the differences discussed below. Inparticular, clamp arm (14244) of end effector (14240) is operable tocompress tissue against blade (14260). When blade (14260) is activatedwhile clamp arm (14244) compresses tissue against blade (14260), endeffector (14240) simultaneously severs the tissue and denatures theproteins in adjacent tissue cells, thereby providing a coagulativeeffect.

Clamp arm (14244) is operable to selectively pivot toward and away fromblade (14242) to selectively clamp tissue between clamp pad (14245) andblade (14260), in a manner substantially similar to clamp arm (44).Clamp arm (14244) is coupled to a trigger (e.g., trigger (28)) such thatclamp arm (14244) is pivotable toward ultrasonic blade (14260) inresponse to pivoting of trigger (28) toward pistol grip (24); and suchthat clamp arm (14244) is pivotable away from ultrasonic blade (14260)in response to pivoting of trigger (28) away from pistol grip (24). Asbest seen in FIGS. 210-211, a cable (14274) is secured to a lower distalshaft element (14270). Cable (14274) is operable to translatelongitudinally relative to an articulation section (14210) of shaftassembly (14200) to selectively pivot clamp arm (14244) toward and awayfrom blade (14260). In particular, cable (14274) is coupled with trigger(28) such that cable (14274) translates proximally in response topivoting of trigger (28) toward pistol grip (24), and such that clamparm (14244) thereby pivots toward blade (14260) in response to pivotingof trigger (28) toward pistol grip (24). In addition, cable (14274)translates distally in response to pivoting of trigger (28) away frompistol grip (24), such that clamp arm (14244) pivots away from blade(14260) in response to pivoting of trigger (28) away from pistol grip(24). Clamp arm (14244) may be biased toward the open position, suchthat (at least in some instances) the operator may effectively openclamp arm (14244) by releasing a grip on trigger (28). Various suitableways in which clamp arm (14244) may be coupled with trigger (28) will beapparent to those of ordinary skill in the art in view of the teachingsherein.

In the example shown, cable (14274) is secured to a proximal end of alower distal shaft element (14270), which is configured in a mannersubstantially similar to lower distal shaft element (170). In thatregard, lower distal shaft element (14270) comprises a pair of distalflanges (not shown) extending from a semi-circular base. The flangeseach comprise a respective opening (not shown). Clamp arm (14244) isrotatably coupled to lower distal shaft element (14270) via a pair ofinwardly extending integral pins (not shown). The pins extend inwardlyfrom arms (14256) of clamp arm (14244) and are rotatably disposed withinrespective openings of lower distal shaft element (14270). In a mannersimilar to that shown in FIGS. 205A-C, longitudinal translation of cable(14274) causes longitudinal translation of lower distal shaft element(14270) between a proximal position and a distal position. Longitudinaltranslation of lower distal shaft element (14270) causes rotation ofclamp arm (14244) between a closed position and an open position.

Shaft assembly (14200) further comprises a pair of articulation bands(14212, 14214). Distal ends of articulation bands (14212, 14214) aresecured to distal flex member (14302) of articulation section (14210).Articulation bands (14212, 14214) are configured to operatesubstantially similar to articulation bands (140, 142) discussed aboveexcept for the differences discussed below. In particular, as shown bestin FIGS. 227A-228B, articulation bands (14212, 14214) are permitted tocause articulation of articulation section (14210) in only onedirection, as discussed in more detailed below. When articulation bands(14212, 14214) are translated longitudinally in an opposing fashion, amoment is created and applied to distal flex member (14302) and alsodistal outer sheath (14202), and also to other components of thearticulation section (14210) due to the operable coupling among thedistal flex member (14302), distal outer sheath (14202), and othercomponents of articulation section (14210). This causes articulationsection (14210) and narrowed section (14249) of flexible portion (14248)of waveguide (14280) to articulate, without transferring axial forces inarticulation bands (14212, 14214) to waveguide (14246).

As shown in FIGS. 209-211, articulation section (14210) comprises adistal flex member (14302), a proximal flex member (14304), and aplurality of flex base members (14306 a-c). Articulation section (14210)further comprises distal outer sheath (14202), a proximal outer sheath(14204), and flex rings (14206 a-c). Articulation section (14210) alsoincludes a flexible collar (14300) that is configured to operably couplecertain components of the articulation section (14210) to one another,as discussed in more detail below. Distal flex member (14302) isoperably coupled to the distal ends of a respective articulation band(14212, 14214). Flex base members (14304 a-c) are positioned proximallyrelative to the distal flex member (14302), and proximal flex member(14304) positioned proximal of flex base members (14306 a-c). Distalflex member (14302), proximal flex member (14304), and flex base members(14306 a-c) collectively define opposing channels (14308, 14310) forreceiving articulation bands (14212, 14214), respectively.

FIGS. 212-213 show distal flex member (14302) of the present example inmore detail. As shown, distal flex member (14302) includes a proximalend (14314), a distal end (14316), and a generally U-shaped body (14318)that defines a space (14319) configured for receiving at least a portionof waveguide (14280). A bottom portion of distal flex member (14302)includes a longitudinally extending recess (14320) that is configured toreceive cable (14274). Each side of distal flex member (14302) includesa channel (14322) that is shaped and configured for receiving a distalend of a respective articulation band (14212, 214). Each channel (14322)includes an aperture (14324) that is configured to receive a portion ofa fastener (14325) (FIG. 210) for coupling a respective articulationband (14212, 14214) to a side of the distal flex member (14302). By wayof example only, fastener (14325) may comprise a pin, a rivet, and/orany other suitable kind of structure.

Space (14319) for receiving waveguide (14280) includes a firstdimensioned portion (14326) that receives a distal portion of waveguideand a second dimensioned portion (14328), which includes a smallerdimension than first dimensioned portion (14326). Second dimensionedportion (14328) is configured to receive narrowed section (14264) ofwaveguide (14280). Notably, however, distal flex member (14302) does notcontact waveguide (14280). Second dimensioned portion (14326) is definedby a pair of opposing angled flanges (14330) which extend radiallyinwardly toward a central longitudinal axis of distal flex member(14302). Angled flanges (14330) define a tapered transition portionbetween the first dimensioned portion (14326) and second dimensionedportion (14328). Second dimensioned portion (14328) is further definedby a pair of flanges (14332), which also extend radially inwardly towardthe central longitudinal axis of distal flex member (14302), at theproximal end (14314) of distal flex member (14302). Flanges (14330,14332) define a pair of opposing slots (14334) that extend along a planethat is parallel to the longitudinal axis of distal flex member. Eachslot (14334) includes an aperture (14336). Various suitable ways inwhich distal flex member (14302) may be configured will be apparent tothose of ordinary skill in the art in view of the teachings herein.

FIGS. 214-215 show proximal flex member (14304) of the present examplein more detail. As shown, proximal flex member (14304) includes aproximal end (14338), a distal end (14340) and a generally U-shaped body(14342) that defines a space (14343) configured for receiving at least aportion of waveguide (14280). A bottom portion of proximal flex member(14302) includes a longitudinal recess (14344) that is configured toreceive cable (14274). Each side of proximal flex member (14304)includes a channel (14346) that is shaped and configured for receivingportion of a respective articulation band (14212, 14214) (and whichforms a portion of channels (14308, 14310)). Each channel (14346) isdefined in part by an upper, shelf (14348) and a lower shelf (14350).

The space (14343) of proximal flex member (14304) for receivingwaveguide (14280) includes a first dimensioned portion (14352) thatreceives a portion of waveguide (14280) and a second dimensioned portion(14354), which includes a smaller dimension than first dimensionedportion (14326). Second dimensioned portion (14354) is configured toreceive narrowed section (14264) of waveguide (14280), though proximalflex member (14304) does not contact waveguide (14280). Seconddimensioned portion (14354) is defined by a pair of opposing angledflanges (14356) which extend radially inwardly toward a centrallongitudinal axis of proximal flex member (14304). Angled flanges(14356) define a tapered transition portion between the firstdimensioned portion (14352) and second dimensioned portion (14354).Second dimensioned portion (14354) is further defined by a pair offlanges (14358), which also extend radially inwardly toward the centrallongitudinal axis of proximal flex member (14304), at the distal end(14340) of proximal flex member (14304). Flanges (14356, 14358) define apair of opposing slots (14360). Each slot (14360) includes a generallyrectangular aperture (14362). Various suitable ways in which proximalflex member (14304) may be configured will be apparent to those ofordinary skill in the art in view of the teachings herein.

Flex base members (14306 a-c), as shown in more detail in FIGS.216-218B, define a single, unitary body (14364) comprising three members(14306 a-c), with living hinges (14366) between adjoining members (14306a-c). However, in other examples, flex base members (14306 a-c) may beseparate, individual members. In the example shown, body (14364) isgenerally U-shaped and defines a space (14368) configured for receivingat least a portion of waveguide (14280). However, body (14364) does notcontact waveguide (14280). A bottom portion of each flex base member(14306 a-c) includes a longitudinal recess (14370) configured to receivecable (14274). Each side of each base member (14306 a-c) includes aradially outwardly extending shelf (14372), each of which defines aboundary on each side of the base members (14306 a-c) for receiving aportion of a respective articulation band (14212, 14214). Each basemember (14306 a-c) includes a respective pair of opposing distal flanges(14374) and a respective pair of opposing proximal flanges (14376)extending radially inwardly toward a central longitudinal axis of body(14364). The distal and proximal flanges (14374, 14376) in each pair offlanges (14374, 14376) define a slot (14378) therebetween. Each slot(14378) includes a generally rectangular aperture (14380).

Each base member (14306 a-c) includes a respective first distal faceportion (14382 a), a second distal face portion (14382 b), a firstproximal face portion (14384 a), and a second proximal face portion(14384 b). As shown best in FIG. 218B, base members (14306 a-c) areconfigured to transition to a flexed position from an unflexed position(FIG. 218A) when, for example, articulation bands (14212, 14214) aremoved longitudinally relative to one another. In the unflexed position,there is a gap between adjacent first proximal and distal faces (14384a, 14382 a); and between second proximal and distal faces (14384 b,14382 b). First distal faces (14382 a) and second distal faces (14382 b)are disposed at an oblique angle (θ_(218A-1)) relative to an imaginaryplane that is perpendicular to the longitudinal axis of base members(14306 a-c). First proximal edges (14384 a) and first proximal edges(14384 b) are disposed at an oblique angle (θ_(218A-2)) relative to animaginary plane that is perpendicular to the longitudinal axis of basemembers (14306 a-c). In the present example, angle (θ_(218A-1)) andangle (θ_(218A-2)) are substantially equal. Thus, the angle betweenadjacent first proximal and distal edges (14384 a, 14382 a) in anunflexed position; and between adjacent second proximal and distal edges(14384 b, 14382 b) in an unflexed position, is θ_(218A-1)+θ_(218A-2).

As shown in FIG. 218B, base members (14306 a-c) are in a flexed positionafter pivoting in one direction relative to a central longitudinal axisabout living hinges (14366), such that first proximal faces (14384 a)substantially abut respective first distal faces (14382 a) of anadjoining base member (14306 a-c). It will be understood that in someversions, base members (14306 a-c) may pivot in an opposite direction,for example, such that second proximal faces (14382 b) substantiallyabut respective second distal faces (14382 b) of an adjoining basemember (14306 a-c). However, in the present example, as will beunderstood from the discussion below, other components of articulationsection (14210) may effectively allow base members (14306 a-c) to pivotin only one direction. Various suitable ways in which flex base members(14306 a-c) may be configured will be apparent to those of ordinaryskill in the art in view of the teachings herein.

Still referring to FIGS. 209-211, articulation section (14210) of thepresent example also includes a distal outer sheath (14202), a proximalouter sheath (14204), and flex rings (14206 a-c) that at least partiallysurround other components of articulation section (14210). Referringalso to FIGS. 219-220 and 227A-228B, distal outer sheath (14202) of thepresent example more particularly comprises a proximal end (14386), adistal end (14388), and a lumen (14390) extending therebetween. At leasta first portion (14392) of a proximal edge of distal outer sheath(14202) extends along an imaginary plane (14393) that is perpendicularto the longitudinal axis of distal outer sheath (14202), while a secondportion (14394) of proximal edge extends at angle (θ₂₂₀) relative toplane (14393). Distal outer sheath (14202) of the present examplefurther comprises a longitudinal channel (14396) extending from theproximal edge (14392) in a direction parallel to a longitudinal axis ofdistal outer sheath (14202). Longitudinal channel (14396) terminates ata transverse channel (14398). Transverse channel (14398) of the presentexample extends parallel to the plane (14393) but perpendicular tolongitudinal channel (14396).

Distal outer sheath (14202) is coupled to waveguide (14280) via anelastomeric ring (14403), which is positioned about distal flange(14236) of waveguide (14280). Thus, as discussed in more detail below,when distal outer sheath (14202) is laterally deflected by thearticulation of articulation section (14210), distal outer sheath(14202) transfers that lateral deflection to waveguide (14280), therebyarticulating end effector (14240).

Distal outer sheath (14202) of the present example further comprises apair of apertures (14400), which are generally rectangular in shape, andspaced laterally from one another and from longitudinal cutout (14396).Distal outer sheath (14202) further includes a plurality ofcircumferentially spaced obround apertures (14402). As shown, in thepresent example, there are six obround apertures (14402), but in otherexamples, there may be more or less than six obround apertures (14402).Longitudinally between obround apertures (14402) and proximal end(14386), distal tube member includes a pair of angularly spaced,generally rectangular apertures (14404). Various suitable ways in whichdistal outer sheath (14202) may be configured will be apparent to thoseof ordinary skill in the art in view of the teachings herein.

Proximal outer sheath (14204) of the present example, referring to FIGS.209-211 and 221-222, is suitable for incorporation into instrument (10)in a manner substantially similar to outer sheath (32). Proximal outersheath (14204) is substantially similar to outer sheath (32), except forthe differences discussed herein. Particularly, proximal outer sheath(14204) includes a proximal end (not shown), a distal end (14406), and alumen (14408) extending therebetween. As best seen in FIG. 222, a firstportion (14410) of distal edge extends along an imaginary plane (14411)that is perpendicular to the longitudinal axis of proximal outer sheath(14204), while a second portion (14412) of distal edge (14410) extendsat an oblique angle (θ₂₂₂) relative to plane (14412). Proximal outersheath (14204) further comprises a longitudinal channel (14414)extending from distal edge (14410) in a direction parallel to alongitudinal axis of proximal outer sheath (14204). Longitudinal channel(14414) terminates at a transverse channel (14416). Transverse channel(14416) of the present example extends parallel to plane (14412) butperpendicular relative to longitudinal channel (14414). Proximal outersheath (14204) of the present example further comprises a pair ofapertures (14419), which are generally rectangular in shape, and spacedlaterally from one another and from longitudinal cutout (14414). Varioussuitable ways in which proximal outer sheath (14204) may be configuredwill be apparent to those of ordinary skill in the art in view of theteachings herein.

As shown in FIGS. 209-211, distal, middle, and proximal flex rings(14206 a-c) are positioned between distal outer sheath (14202) andproximal outer sheath (14204) such that flex rings (14206 a-c), distalouter sheath (14202), and proximal outer sheath (14204) define at leasta portion of a radially outward boundary of shaft assembly (14200). Flexrings (14206 a-c) define a single, unitary body (14364) comprising threemembers (14306 a-c), with living hinges (14366) between adjoining flexrings (14206 a-c). However, in other examples, flex rings (14206 a-c)may be separate, individual members. Referring also to FIGS. 223-224B,three flex rings (14206 a-c) are shown, but it will be understood thatthere may be more or less than three flex rings (14206 a-c). In thepresent example, each flex ring (14206 a-c) includes a first portion(14418) that is partially circular in cross-section and a pair offlanges (14420). The flanges (14420) of each pair of flanges (14420)extend radially inwardly from each end of the first portion (14418)toward one another, and along a plane extending parallel to alongitudinal axis of each flex ring (14206). Each flange (14420)includes a generally rectangular aperture (14421) extendingtherethrough.

Each flex ring (14206 a-c) includes a first distal edge portion (14422a), second distal edge portion (14422 b), first proximal edge portion(14424 a), and second proximal edge portion (14424 b). In the presentexample, first distal edge portion (14422 a) extends at an oblique anglerelative to second distal edge portion (14422 b). Second distal edgeportion (14422 b) of each flex ring (14206 a-c) extends along a firstplane (14426) that is perpendicular to the longitudinal axis of eachflex ring (14206 a-c). Thus, the first distal edge portion (14422 a)extends at an oblique angle (θ_(224A-1)) relative to a first plane(14426) that is perpendicular to the longitudinal axis of each flex ring(14206). Similarly, first proximal edge portion (14424 a) extends at anoblique angle relative to second proximal edge portion (14424 b). Secondproximal edge portion (14424 b) extends along a second plane (14428)that is perpendicular to the longitudinal axis of each flex ring (14206a-c). Thus, the first proximal edge portion (14424 a) of each flex ring(14206 a-c) extends at an oblique angle (θ_(224A-2)) relative to itssecond proximal edge portion (14424 b).

When assembled as shown in FIGS. 209-210, the distal most flex ring (206a) is substantially abutted distally by distal outer sheath (14202)(force represented by arrow (14430) in FIG. 224A), while the proximalmost flex ring (14206 c) is substantially abutted proximally by proximalouter sheath (14204) (force represented by arrow (14432) in FIG. 224A).Flex rings (14206 a-c) are configured to transition to a flexed position(FIG. 224B) from an unflexed position (FIG. 224A) when, for example,articulation bands (14212, 14214) are moved longitudinally relative toone another, as discussed in more detail below. However, second distaledge portions (14424 a) and second proximal edge portions (14424 b)interact with one another and with distal outer sheath (14202) andproximal outer sheath (14204) to act as positive stops to restrictpivoting of flex rings (14206 a-c) to a single direction. As shown,longitudinal axis (14425) intersects the points of each flex ring (14206a-c) where the respective first and second distal portions (14422 a,14422 b) meet, and where the respective first and second proximalportions (14424 a, 14424 b) meet. Because adjacent second distal andproximal portions (14422 b, 14424 b) act as a positive stop against oneanother (and also with adjacent distal and proximal tube members (14202a, 14202 b)), flex rings are substantially prevented from pivoting alonga path that is above axis (14425) (“above” direction represented byarrow (14435)). Therefore, in the present example, due to the operativecoupling of flex rings (14206 a-c) to other components of articulationmechanism (14210), articulation mechanism (14210) is permitted toarticulate in only one direction (opposite to arrow (14435)) and mayonly pivot about axes (14427, 14429)).

Flex rings (14206 a-c) are rigid in the present example such that anyattempted articulation in the opposite direction does not substantiallyoccur due to the material properties of flex rings (14206 a-c). That is,where articulation bands (14212, 14214) are moved in a manner thatcauses a moment in the opposite direction, the material properties(rigidity, stiffness, etc.) of flex rings (14206 a-c) are configured toprevent bending, buckling, compression, etc., of the flex rings (14206a-c) that may cause a certain amount of articulation in the direction ofarrow (14435). Various suitable ways in which flex rings (14206 a-c) maybe configured will be apparent to those of ordinary skill in the art inview of the teachings herein.

FIGS. 209-211 and 225-228B show collar (14300) of the present example.As noted above, collar (14300) is configured to operably couple certaincomponents of the articulation section (14210) to one another. Collar(14300) of the present example is further configured to couple distalouter sheath (14202) with proximal outer sheath (14204). As best shownin FIGS. 225-226, collar (14434) includes a proximal end (14436), and adistal end (14438), and a body (14440) extending therebetween. In thepresent example, collar (14300) includes a spine portion (14442)extending along a longitudinal axis and five pairs of opposing legs(14444 a-e) extending from the spine portion (14442). Collar (14300)also includes an elongate rib (14443) extending along the axis of thecollar (14300). Each of the five pairs of legs (14444 a-e) are spacedapart equally along a longitudinal axis of the collar (14300). As shown,there are five pairs of opposing legs, but there may be more or lessthan five pairs of legs, and the pairs of opposing legs may or may notbe equally spaced longitudinally. In the present example, each pair oflegs includes a first leg that extends away from the spine (14442) in afirst direction and a second leg extending away from the spine in seconddirection. Each of the first and second legs of each pair includecurvilinear portions and are configured such that the first and secondlegs of each pair eventually extend parallel to one another. Each of thelegs (14444 a-e) includes a respective snap-fit feature (14446 a-e)defining respective angled portions (14448 a-e) and lip portions (14450a-e). In some examples, angled portions (14448 a-e) are configured toact as cam members, in order to assist the collar (14300) to be coupledwith other components of the articulation section. More particularly,angled portions (14448 a-e) may act as cam members when being directedinto respective slots and apertures, and legs (14444 a-e) may flexinwardly temporarily as collar (14300) is being directed into engagementwith certain components to provide a snap fit engagement. Varioussuitable ways in which collar (14300) may be configured will be apparentto those of ordinary skill in the art in view of the teachings herein

The operable coupling of components of the articulation section (14210)allows the articulation section (14210) to articulate when a moment isapplied directly to one or more components of the articulation section(14210). Referring to FIGS. 209-211, 227A and 228A, in the presentexample, in the unarticulated configuration, proximal end (14314) ofdistal flex member (14302) substantially abuts flex base member (14306a), particularly at the point where first distal portion (14382 a) meetssecond distal portion (14382 b). Distal end (14340) of proximal flexmember (14304) substantially abuts flex base member (14306 c),particularly where first proximal portion (14384 a) meets secondproximal portion (14384 b). As discussed above, flex base member (14306b) is between flex base member (14306 a) and flex base member (14306 c).

In the present example, lumen (14390) of distal tube member (14302)coaxially receives distal flex member (14302) such that slots (14334) ofdistal flex member (14302) generally align with apertures (14400) ofdistal outer sheath (14202). Legs (14444 a) extend into apertures(14400) and along slots (14334) such that lip portion (14450 a) engagesa portion of aperture (14336) and thereby secures collar (14300), distalflex member (14302), and distal outer sheath (14202) to one another.Lumen (14408) of proximal outer sheath (14204) receives proximal flexmember (14304) such that slots (14360) of proximal flex member (14304)generally align with apertures (14419) of proximal tube member. Legs(14444 e) extend into apertures (14419) and along slots (14360) suchthat lip portion (14450 e) engages a portion of aperture (14362) andthereby secures collar (14300), proximal flex member (14304), andproximal outer sheath (14204) to one another.

Flex base members (14306 a-c) of the present example are coaxiallyreceived in flex rings (14206 a-c) such that flex base member (14306 a)is coincident with flex ring (14206 a), flex base member (14306 b) iscoincident with flex ring (14206 b), and flex base member (14306 c) iscoincident with flex ring (14206 c). Therefore, in such a configuration,apertures (14421) of each flex ring (14206 a-c) generally align withslots (14378) of a respective flex base member (14306 a-c). Legs (14444b) extend into apertures (14421) of flex ring (14206 a) and along slots(14378) of flex base member (14306 a) such that lip portions (14450 b)engage a portion of a respective aperture (14380). Similarly, legs(14444 c) extend into apertures (14421) of flex ring (14206 b) and alongslots (14378) of flex base member (14306 b) such that lip portions(14450 c) engage a portion of a respective aperture (14380). Similarly,legs (14444 d) extend into apertures of flex ring (14206 b) and alongslots (14378) of flex base member (14306 c) such that lip portions(14450 d) engage a portion of a respective aperture (14380).

Still referring to FIGS. 209-211, 227A, and 228A, in the presentexample, in the unarticulated configuration, first portion (14392) ofproximal edge of distal outer sheath (14202) substantially abuts seconddistal portion (14422 b) of flex ring (14206 a). Second proximal portion(14424 b) of flex ring (14206 a) substantially abuts second distalportion (14422 b) of flex ring (14206 b). Similarly, second proximalportion (14424 b) of flex ring (14206 b) substantially abuts seconddistal portion (14422 b) of flex ring (14206 c). Second proximal portion(14424 b) of flex ring (14206 b) substantially abuts first portion(14210) of distal edge of proximal outer sheath (14204). Varioussuitable ways in which articulation section (14210) may be configuredwill be apparent to those of ordinary skill in the art in view of theteachings herein.

In the present example, as articulation bands (14212, 14214) are movedlongitudinally relative to one another, a moment is initially applied todistal flex member (14302). Due to the distal flex member (14302), flexbase members (14306 a-c), proximal flex member (14304), distal outersheath (14202), flex rings (14206 a-c), and proximal outer sheath(14304) being operably coupled via collar (14300) in the mannerdescribed herein, the moment applied to distal flex member (14302) istransferred to the collar (14300), distal flex member (14302), flex basemembers (14306 a-c), proximal flex member (14304), distal outer sheath(14202), flex rings (14206 a-c), and proximal outer sheath (14204).Thus, articulation section (14210) transitions to an articulatedconfiguration, as best shown in FIGS. 227B, 228B. In the articulatedconfiguration, articulation section (14210) articulates in the samedirection away from the longitudinal axis of instrument (10) as thedirection of the bend angle (A) of blade (14260).

As shown in FIGS. 227B and 228B, as a result of the moment applied ontothe components of articulation section (14210), distal outer sheath(14202) is pivoted relative to flex ring (14206 a) such that secondportion (14394) of distal edge of distal outer sheath (14202)substantially abuts first distal portion (14422 a) of flex ring (14206a). Flex ring (14206 a) is shown to be pivoted relative to flex ring(14206 b) such that first proximal portion (14424 a) of flex ring (14206b) substantially abuts first distal portion (14422 a) of flex ring(14206 b). Flex ring (14206 b) is shown pivoted relative to flex ring(14206 c) such that first proximal portion (14424 a) of flex ring (14206b) substantially abuts first distal portion (14422 a) of flex ring(14206 c). Flex ring (14206 c) is shown to be pivoted such that firstproximal portion (14424 a) of flex ring (14206 c) substantially abutssecond portion (14412) of distal edge of proximal outer sheath (14204).Thus, in the present example, the maximum articulation angle (asmeasured between a central axis of distal outer sheath (14202) relativeto a central axis of proximal outer sheath (14204)) due to the abutmentof such structures is θ_(Δ), whereθ_(Δ)=3*(θ_(224A-1)+θ_(224A-2))−θ₂₂₂−θ₂₂₀.

Once the articulation bands (14212, 14214) move relative to one anotherin a manner opposite to that which caused the articulation, articulationsection (14210) may return to the unarticulated configuration shown inFIGS. 227A and 228A. However, even if the operator somehow attempts tocontinue opposingly move articulation bands (14212, 14214) oncearticulation section (14210) reaches the unarticulated configurationshown in FIGS. 227A and 228A, engagement between adjacent edge portions(14422 b, 14424 b) will prevent articulation section (14210) fromarticulating past longitudinal axis (14425) in the direction of arrow(14435).

XVI. ULTRASONIC SURGICAL INSTRUMENT WITH OPPOSING THREAD DRIVE FOR ENDEFFECTOR ARTICULATION

A. Exemplary Alternative Articulation Control Configurations withPerpendicular Rotary Knob

When an operator wishes to control articulation of articulation section(130) in instrument (10) as described above, the operator may need touse both hands. In particular, the operator may need to grasp pistolgrip (24) with one hand and grasp knob (120) with the other hand,holding handle assembly (20) stationary via pistol grip (24) while theoperator rotates knob (120). It may be desirable to provide control ofarticulation section (130) without requiring the operator to use bothhands. This may enable the operator to have a free hand to grasp otherinstruments or otherwise use as they see fit. An exemplary alternativeinstrument (15200) is described below in which an operator may firmlygrasp the instrument (15200) and control articulation of an articulationsection using just one single hand. Various suitable ways in which thebelow teachings may be modified will be apparent to those of ordinaryskill in the art in view of the teachings herein.

FIGS. 229-245C depict an exemplary electrosurgical instrument (15200)that includes a handle assembly (15220), a shaft assembly (15230)extending distally from handle assembly (15220), and an end effector(15240) disposed at a distal end of shaft assembly (15230). Handleassembly (15220) of the present example comprises a body (15222)including a pistol grip (15224) and a button (15226). Handle assembly(15220) also includes a trigger (15228) that is pivotable toward andaway from pistol grip (15224) to selectively actuate end effector(15240) as described above and as described in one or more of thereferences cited herein. It should be understood, however, that variousother suitable configurations may be used, including but not limited toa scissor grip configuration. End effector (15240) includes anultrasonic blade (15260) and a pivoting clamp arm (15244). Clamp arm(15244) is coupled with trigger (15228) such that clamp arm (15244) ispivotable toward ultrasonic blade (15260) in response to pivoting oftrigger (15228) toward pistol grip (15224); and such that clamp arm(15244) is pivotable away from ultrasonic blade (15260) in response topivoting of trigger (15228) away from pistol grip (15224). Varioussuitable ways in which clamp arm (15244) may be coupled with trigger(15228) will be apparent to those of ordinary skill in the art in viewof the teachings herein. In some versions, one or more resilient membersare used to bias clamp arm (15244) and/or trigger (15228) to the openposition shown in FIGS. 229 and 230.

An ultrasonic transducer assembly (15212) extends proximally from body(15222) of handle assembly (15220). Transducer assembly (15212) iscoupled with a generator (15216) via a cable (15214), such thattransducer assembly (15212) receives electrical power from generator(15216). Piezoelectric elements in transducer assembly (15212) convertthat electrical power into ultrasonic vibrations. Generator (15216) mayinclude a power source and control module that is configured to providea power profile to transducer assembly (15212) that is particularlysuited for the generation of ultrasonic vibrations through transducerassembly (15212). By way of example only, generator (15216) may comprisea GEN 300 sold by Ethicon Endo-Surgery, Inc. of Cincinnati, Ohio. Inaddition or in the alternative, generator (15216) may be constructed inaccordance with at least some of the teachings of U.S. Pub. No.2011/0087212, now issued as U.S. Pat. No. 8,986,302 on Mar. 24, 2015,entitled “Surgical Generator for Ultrasonic and ElectrosurgicalDevices,” published Apr. 14, 2011, the disclosure of which isincorporated by reference herein. It should also be understood that atleast some of the functionality of generator (15216) may be integratedinto handle assembly (15220), and that handle assembly (15220) may eveninclude a battery or other on-board power source such that cable (15214)is omitted. Still other suitable forms that generator (15216) may take,as well as various features and operabilities that generator (15216) mayprovide, will be apparent to those of ordinary skill in the art in viewof the teachings herein.

An operator may activate button (15226) to selectively activatetransducer assembly (15212) to thereby activate ultrasonic blade(15260). In the present example, a single button (15226) is provided.Button (15226) may be depressed to activate ultrasonic blade (15260) ata low power and to activate ultrasonic blade (15260) at a high power.For instance, button (15226) may be pressed through a first range ofmotion to activate ultrasonic blade (15260) at a low power; and througha second range of motion to activate ultrasonic blade (15260) at a highpower. Of course, any other suitable number of buttons and/or otherwiseselectable power levels may be provided. For instance, a foot pedal maybe provided to selectively activate transducer assembly (15212). Button(15226) of the present example is positioned such that an operator mayreadily fully operate instrument (15200) with a single hand. Forinstance, the operator may position their thumb about pistol grip(15224), position their middle, ring, and/or little finger about trigger(15228), and manipulate button (15226) using their index finger.Alternatively, any other suitable techniques may be used to grip andoperate instrument (15200); and button (15226) may be located at anyother suitable positions.

In some versions, button (15226) also serves as a mechanical lockoutagainst trigger (15224), such that trigger (15224) cannot be fullyactuated unless button (15226) is being pressed simultaneously. Examplesof how such a lockout may be provided are disclosed in one or more ofthe references cited herein. It should be understood that pistol grip(15222), trigger (15224), and button (15226) may be modified,substituted, supplemented, etc. in any suitable way, and that thedescriptions of such components herein are merely illustrative.

1. Exemplary End Effector and Acoustic Drivetrain

As best seen in FIGS. 229 and 230, end effector (15240) of the presentexample comprises clamp arm (15244) and ultrasonic blade (15260). Clamparm (15244) includes a clamp pad (15246) that is secured to theunderside of clamp arm (15244), facing ultrasonic blade (15260). Clamppad (15246) may comprise PTFE and/or any other suitable material(s).Clamp arm (15244) is operable to selectively pivot toward and away fromultrasonic blade (15260) to selectively clamp tissue between clamp arm(15244) and blade (15260).

As with clamp arm (15044) discussed above, clamp arm (15244) of thepresent example is pivotally secured to a cable (15274). Cable (15274)is slidably disposed within an outer sheath (15232) of shaft assembly(15230) as shown in FIGS. 233-234. Cable (15274) is operable totranslate longitudinally relative to an articulation section (15330) ofshaft assembly (15230) to selectively pivot clamp arm (15244) toward andaway from blade (15260). In particular, cable (15274) is coupled withtrigger (15228) such that cable (15274) translates proximally inresponse to pivoting of trigger (15228) toward pistol grip (15224), andsuch that clamp arm (15244) thereby pivots toward blade (15260) inresponse to pivoting of trigger (15228) toward pistol grip (15224). Inaddition, cable (15274) translates distally in response to pivoting oftrigger (15228) away from pistol grip (15224), such that clamp arm(15244) pivots away from blade (15260) in response to pivoting oftrigger (15228) away from pistol grip (15224). Clamp arm (15244) may bebiased toward the open position, such that (at least in some instances)the operator may effectively open clamp arm (15244) by releasing a gripon trigger (15228). It should be understood that clamp arm (15244) ismerely optional, such that clamp arm (15244) may be omitted if desired.

Blade (15260) of the present example is operable to vibrate atultrasonic frequencies in order to effectively cut through and sealtissue, particularly when the tissue is being compressed between clamppad (15246) and blade (15260). Blade (15260) is positioned at the distalend of an acoustic drivetrain. This acoustic drivetrain includestransducer assembly (15212) and an acoustic waveguide (15280). Acousticwaveguide (15280) comprises a flexible portion (15266). Transducerassembly (15212) includes a set of piezoelectric discs (not shown)located proximal to a horn (not shown) of waveguide (15280). Thepiezoelectric discs are operable to convert electrical power intoultrasonic vibrations, which are then transmitted along waveguide(15280), including flexible portion (15266) of waveguide (15280) toblade (15260) in accordance with known configurations and techniques. Byway of example only, this portion of the acoustic drivetrain may beconfigured in accordance with various teachings of various referencesthat are cited herein.

As with flexible portion (166) of waveguide (180) discussed above,flexible portion (15266) of waveguide (15280) includes a narrowedsection (15264). Narrowed section (15264) is configured to allowflexible portion (15266) of waveguide (15280) to flex withoutsignificantly affecting the ability of flexible portion (15266) ofwaveguide (15280) to transmit ultrasonic vibrations. By way of exampleonly, narrowed section (15264) may be configured in accordance with oneor more teachings of U.S. Pub. No. 2014/0005701, issued as U.S. Pat. No.9,393,037 on Jul. 19, 2016, and/or U.S. Pub. No. 2014/0114334, issued asU.S. Pat. No. 9,045,367 on Aug. 4, 2015, the disclosures of which areincorporated by reference herein. It should be understood that waveguide(15280) may be configured to amplify mechanical vibrations transmittedthrough waveguide (15280). Furthermore, waveguide (15280) may includefeatures operable to control the gain of the longitudinal vibrationsalong waveguide (15280) and/or features to tune waveguide (15280) to theresonant frequency of the system. Various suitable ways in whichwaveguide (15280) may be mechanically and acoustically coupled withtransducer assembly (15212) will be apparent to those of ordinary skillin the art in view of the teachings herein.

In the present example, the distal end of blade (15260) is located at aposition corresponding to an anti-node associated with resonantultrasonic vibrations communicated through flexible portion (15266) ofwaveguide (15280), in order to tune the acoustic assembly to a preferredresonant frequency f_(o) when the acoustic assembly is not loaded bytissue. When transducer assembly (15212) is energized, the distal end ofblade (15260) is configured to move longitudinally in the range of, forexample, approximately 10 to 500 microns peak-to-peak, and in someinstances in the range of about 20 to about 200 microns at apredetermined vibratory frequency f_(o) of, for example, 55.5 kHz. Whentransducer assembly (15212) of the present example is activated, thesemechanical oscillations are transmitted through waveguide (15280) toreach blade (15260), thereby providing oscillation of blade (15260) atthe resonant ultrasonic frequency. Thus, when tissue is secured betweenblade (15260) and clamp pad (15246), the ultrasonic oscillation of blade(15260) may simultaneously sever the tissue and denature the proteins inadjacent tissue cells, thereby providing a coagulative effect withrelatively little thermal spread. In some versions, an electricalcurrent may also be provided through blade (15260) and clamp arm (15244)to also cauterize the tissue. While some configurations for an acoustictransmission assembly and transducer assembly (15212) have beendescribed, still other suitable configurations for an acoustictransmission assembly and transducer assembly (15212) will be apparentto one or ordinary skill in the art in view of the teachings herein.Similarly, other suitable configurations for end effector (15240) willbe apparent to those of ordinary skill in the art in view of theteachings herein.

2. Exemplary Shaft Assembly and Articulation Section

Shaft assembly (15230) of the present example extends distally fromhandle assembly (15220). As best seen in FIGS. 229 and 230, shaftassembly (15230) includes distal outer sheath (15233) and a proximalouter sheath (15232) that enclose the drive features of clamp arm(15244) and the above-described acoustic transmission features. Shaftassembly (15230) further includes an articulation section (15330), whichis located at a distal portion of shaft assembly (15230), with endeffector (15240) being located distal to articulation section (15330).

Articulation section (15330) of the present example is configured andoperable substantially similar to articulation section (130) discussedabove except for the differences discussed below. In particular,articulation section (15330) is operable to selectively position endeffector (15240) at various lateral deflection angles relative to alongitudinal axis defined by outer sheath (15232). Articulation section(15330) may take a variety of forms. By way of example only,articulation section (15330) may be configured in accordance with one ormore teachings of U.S. Pub. No. 2012/0078247, issued as U.S. Pat. No.9,402,682 on Aug. 2, 2016, the disclosure of which is incorporated byreference herein. As another merely illustrative example, articulationsection (15330) may be configured in accordance with one or moreteachings of U.S. Pub. No. 2014/0005701, issued as U.S. Pat. No.9,393,037 on Jul. 19, 2016, and/or U.S. Pub. No. 2014/0114334, issued asU.S. Pat. No. 9,095,367 on Aug. 4, 2015, the disclosures of which areincorporated by reference herein. Various other suitable forms thatarticulation section (15330) may take will be apparent to those ofordinary skill in the art in view of the teachings herein.

As shown in FIGS. 233-234, shaft assembly (15230) further comprises apair of articulation bands (15340, 15342) and a pair of translatablerods (15440, 15442). Articulation bands (15340, 15342) are configured tooperate substantially similar to articulation bands (140, 142) discussedabove, except for any differences discussed below. For instance, whenarticulation bands (15340, 15342) translate longitudinally in anopposing fashion, this will cause articulation section (15330) to bend,thereby laterally deflecting end effector (15240) away from thelongitudinal axis of shaft assembly (15230) from a straightconfiguration as shown in FIG. 245A to an articulated configuration asshown in FIGS. 245B and 245C. In particular, end effector (15240) willbe articulated toward the articulation band (15340, 15342) that is beingpulled proximally. During such articulation, the other articulation band(15340, 15342) may be pulled distally. Alternatively, the otherarticulation band (15340, 15342) may be driven distally by articulationcontrol assembly (15400), which is described in greater detail below.Flexible acoustic waveguide (15266) is configured to effectivelycommunicate ultrasonic vibrations from waveguide (15280) to blade(15260) even when articulation section (15330) is in an articulatedstate as shown in FIGS. 245B and 245C.

Translatable members (15440, 15442) are slidably disposed within theproximal portion of outer sheath (15232). Translatable members (15440,15442) extend longitudinally through the proximal portion of outersheath (15232) along opposite sides of outer sheath (15232) and adjacentan interior surface of outer sheath (15232). As shown in FIG. 234, anelongate recess (15444) is formed in an exterior surface of a distalportion of each translatable member (15440, 15442). Elongate recesses(15444) are configured to receive a proximal portion of eacharticulation band (15340, 15342). Each translatable member (440, 15442)further includes a pin (15443) projecting outwardly from an interiorsurface of each elongate recess (15444). An opening (15341) formed in aproximal end of each articulation band (15340, 15342) is configured toreceive a respective pin (15443) of translatable members (15440, 15442).Pins (15443) and openings (15341, 15343) thus function to mechanicallycouple translatable members (15440, 15442) with articulation bands(15340, 15342) such that longitudinal translation of translatable member(15440) causes concurrent longitudinal translation of articulation band(15340), and such that longitudinal translation of translatable member(15442) causes concurrent longitudinal translation of articulation band(15342).

When translatable members (15440, 15442) and articulation bands (15340,15342) are translated longitudinally in an opposing fashion, a moment iscreated and applied to a distal end of distal outer sheath (15233) inthe same manner as described above with respect to articulation section(130). This causes articulation section (15330) and narrowed section(15264) of flexible portion (15266) of waveguide (15280) to articulate,without transferring axial forces in articulation bands (15340, 15342)to waveguide (15280) as described above. It should be understood thatone articulation band (15340, 15342) may be actively driven distallywhile the other articulation band (15340, 15342) is passively permittedto retract proximally. As another merely illustrative example, onearticulation band (15340, 15342) may be actively driven proximally whilethe other articulation band (15340, 15342) is passively permitted toadvance distally. As yet another merely illustrative example, onearticulation band (15340, 15342) may be actively driven distally whilethe other articulation band (15340, 15342) is actively drivenproximally. Various suitable ways in which articulation bands (15340,15342) may be driven will be apparent to those of ordinary skill in theart in view of the teachings herein.

As shown in FIGS. 229-232, a rotation knob (15231) is secured to aproximal portion of proximal outer sheath (15232). Rotation knob (15231)is rotatable relative to body (15222), such that shaft assembly (15230)is rotatable about the longitudinal axis defined by outer sheath(15232), relative to handle assembly (15220). Such rotation may providerotation of end effector (15240), articulation section (15330), andshaft assembly (15230) unitarily. Of course, rotatable features maysimply be omitted if desired.

3. Exemplary Articulation Control Assembly

FIGS. 235-245C show the components and operation of an articulationcontrol assembly (15400) that is configured to provide control forarticulation of articulation section (15330). Articulation controlassembly (15400) comprises an articulation control knob (15402) and abevel gear (15404). Articulation control knob (15402) is rotatablydisposed within a distal portion of body (15222) of handle assembly(15220). As best seen in FIG. 232, articulation control knob (15402) isoriented within body (15222) and relative to shaft assembly (15230) suchthat articulation control knob (15402) is configured to rotate about anaxis that is perpendicular to the longitudinal axis defined by shaftassembly (15230). A portion of articulation control knob (15402) isexposed relative to body (15222) such that an operator may engagearticulation control knob (15402) to thereby rotate articulation controlknob (15402). For example, while gripping body (15222) via pistol grip(15224), an operator may use his or her index finger or thumb to rotatearticulation control knob (15402). It should therefore be understoodthat the operator may rotate knob (15402) using the same hand thatgrasps pistol grip (15224). As will be described in more detail below,rotation of articulation control knob (15402) is configured to causearticulation of articulation section (15330). Since the operator may usethe same hand to rotate knob (15402) and simultaneously grasp pistolgrip (15224), articulation control assembly (15400) of this exampleprovides full control of instrument (15200)—including pivoting oftrigger (15228), actuation of button (15226), and actuation of knob(15402)—with just one single hand, such the operator's other hand may becompletely free during the entire period when any and all functionalityof instrument (15200) is being used.

Articulation control assembly (15400) further includes a structuralframe (15370) secured within a proximal portion of an interior of body(15222) of handle assembly (15220) such that structural frame (15370) isconfigured to remain stationary within body (15222). As best seen inFIGS. 235 and 236, bevel gear (15404) is rotatably disposed about acylindrical projection (15372) of structural frame (15370). As best seenin FIG. 232, bevel gear (15404) is mechanically coupled witharticulation control knob (15402) via a slot (15406) formed in bevelgear (15404) and a mating key (15408) projecting from a top surface ofarticulation control knob (15402) such that rotation of articulationcontrol knob (15402) causes concurrent rotation of bevel gear (15404)about cylindrical projection (15372) of structural frame (15370). Bevelgear (15404) includes a plurality of teeth (15410) and a detent feature(15412). As will be described in more detail below, teeth (15410) ofbevel gear (15404) mesh with teeth (15439) of a bevel gear (15438) of adrive assembly (15420), such that rotation of bevel gear (15404) drivesarticulation of articulation section (15330).

Detent feature (15412) is configured to selectively engage acomplementary, resiliently biased detent feature (15223) of handleassembly (15220) as best seen in FIG. 232. Detent feature (15412) ispositioned to engage detent feature (15223) when control knob (15402) isrotated to a “neutral” position associated with articulation section(15330) being in a straight configuration. It should therefore beunderstood that detent features (15224, 15412) may cooperate to providethe operator with tactile feedback via control knob (15402) to indicatethat articulation section (15330) is in the straight configuration.Detent features (15224, 15412) may also cooperate to provide some degreeof mechanical resistance to rotation of knob (15402) from the neutralposition, thereby resisting inadvertent articulation of articulationsection (15330) that might otherwise result from incidental contactbetween knob (15402) and the operator's hand, etc.

In addition to or in lieu of including detent features (15224, 15412),knob (15402) may include a visual indicator that is associated witharticulation section (15330) being in a substantially straightconfiguration. Such a visual indicator may align with a correspondingvisual indicator on body (15222) of handle assembly (15220). Thus, whenan operator has rotated knob (15402) to make articulation section(15330) approach a substantially straight configuration, the operatormay observe such indicators to confirm whether articulation section(15330) has in fact reached a substantially straight configuration. Byway of example only, this may be done right before instrument (15200) iswithdrawn from a trocar to reduce the likelihood of articulation section(15330) snagging on a distal edge of the trocar. Of course, suchindicators are merely optional.

As best seen in FIG. 235, articulation control assembly (15400) furthercomprises a drive assembly (15420). Drive assembly (15420) is secured toa proximal portion of proximal outer sheath (15232). Drive assembly(15420) is further rotatably disposed within rotation knob (15231) suchthat rotation knob (15231) is configured to rotate independently aboutdrive assembly (15420) to thereby cause rotation of shaft assembly(15230) without causing rotation of drive assembly (15420).

Drive assembly (15420) comprises a housing (15430), a pair of leadscrews (15450, 15460), and a cylindrical guide (15470). Housing (15430)comprises a pair of mating semi-cylindrical shrouding halves (15432,15434) and a bevel gear (15438). When coupled to one another, shroudinghalves (15432, 15434) form a cylindrical shroud (15431). A proximal endof shroud (15431) is coupled with and closed-off by bevel gear (15438).Shroud (15431), together with bevel gear (15438), form housing (15430)which substantially encompasses the internal components of driveassembly (15420) as will be described in more detail below.

Bevel gear (15438) includes a plurality of teeth (15439). Teeth (15439)of bevel gear (15438) are configured to engage teeth (15410) of bevelgear (15404) such that rotation of bevel gear (15404) causes concurrentrotation of bevel gear (15438). It should therefore be understood thatrotation of articulation control knob (15402) is configured to causeconcurrent rotation of housing (15430) via bevel gears (15404, 15438).

As best seen in FIG. 236, shrouding halves (15432, 15434) each includeproximal internal threading (15433A) formed in an interior surface ofeach shrouding half (15432, 15434). Internal threadings (15433A) areconfigured to align with one another when shrouding halves (15432,15434) are coupled together to form a continuous internal proximalthreading (15433) within housing (15430). Shrouding halves (15432,15434) each further include distal internal threading (15435A) formed inan interior surface of each shrouding half (15432, 15434). Internalthreadings (15435A) are configured to align with one another whenshrouding halves (15432, 15434) are coupled together to form acontinuous internal distal threading (15435) within housing (15430).Threadings (15433, 15435) have opposing pitch angles or orientations inthis example, such that the pitch orientation of threading (15433) isopposite the pitch orientation of threading (15435).

As shown in FIGS. 238-239, a first lead screw (15450) includes exteriorthreading (15452) that is configured to engage with threading (15433) ofhousing (15430). As shown in FIGS. 240-241 a second lead screw (15460)includes exterior threading (15462) that is configured to engage withthreading (15435) of housing (15430). The pitch angle of threading(15452) complements the pitch angle of threading (15433); while thepitch angle of threading (15462) complements the pitch angle ofthreading (15435). As described in greater detail below, both leadscrews (15450, 15460) are permitted to translate within drive assembly(15420) but are prevented from rotating within drive assembly (15420).It should therefore be understood that, due to the opposing pitchangles, rotation of housing (15430) in a first direction will drive leadscrew (15450) distally while simultaneously driving lead screw (15460)proximally; and rotation of housing (15430) in a second direction willdrive lead screw (15450) proximally while simultaneously driving leadscrew (15460) distally.

As best seen in FIGS. 239 and 241, a through-bore (15454, 15464) formedin each lead screw (15450, 15460) includes a pair of recesses (15456,15466) formed in radially opposing sides of an interior surface ofthrough-bores (15454, 15464). Cylindrical guide (15470) is positionedwithin housing (15430) about the proximal portion of outer sheath(15232). As shown in FIGS. 242A and 242B, cylindrical guide (15470) issecured to a distal end of structural frame (15370) via a pair ofsemi-circular recesses (15374) formed in the distal end of structuralframe (15370) and a pair of semi-circular projections (15476) extendingproximally from cylindrical guide (15470). Thus, with structural frame(15370) secured within the proximal portion of the interior of body(15222) of handle assembly (15220) as described above, cylindrical guide(15470) is configured to remain stationary within housing (15430). Abearing member (15436) is coupled to a distal end of cylindrical guide(15470) via a pair of semi-circular recesses (15437) formed in bearingmember (15436) and a pair of semi-circular projections (15478) extendingdistally from cylindrical guide (15470). A circular flange (15441) ofbearing member (15436) is rotatable disposed within a pair of matingcircular recesses (15451A) formed in a distal end of shroud halves(15432, 15434) such that housing (15430) is operable to rotate aboutbearing member (15436).

As best seen in FIGS. 242A and 242B, cylindrical guide (15470) comprisesa proximal pair of longitudinal tracks (15472) and a distal pair oflongitudinal tracks (15474) formed in opposing sides of a sidewall ofcylindrical guide (15470). As shown in FIG. 243, proximal longitudinaltracks (15472) are configured to be received within recesses (15456) offirst lead screw (15450) such that first lead screw (15450) is slidablydisposed along proximal longitudinal tracks (15472). As shown in FIG.244, distal longitudinal tracks (15474) are configured to be receivedwithin recesses (15466) of second lead screw (15460) such that secondlead screw (15460) is slidably disposed along distal longitudinal tracks(15474). Thus, lead screws (15450, 15460) are operable to translatewithin housing (15430) but are prevented from rotating within housing(15430).

As shown in FIG. 243, first lead screw (15450) is secured to a proximalend of translatable member (15440) via a coupler (15458). An exteriorsurface of coupler (15458) is secured to an interior surface ofthrough-bore (15454) of first lead screw (15450). A key (15459) ofcoupler (15458) is positioned within a mating slot (15447) formed in theproximal end of translatable member (15440) such that longitudinaltranslation of first lead screw (15450) causes concurrent translation oftranslatable member (15440) and articulation band (15340). Thus, in thepresent version, first lead screw (15450) is operable to both pusharticulation band (15340) distally and pull articulation band (15340)proximally, depending on which direction housing (15430) is rotated.Other suitable relationships will be apparent to those of ordinary skillin the art in view of the teachings herein.

As shown in FIG. 244, second lead screw (15460) is secured to a proximalend of translatable member (15442) via a coupler (15468). An exteriorsurface of coupler (15468) is secured to an interior surface ofthrough-bore (15464) of second lead screw (15460). A key (15469) ofcoupler (15468) is positioned within a mating slot (15449) formed in theproximal end of translatable member (15442) such that longitudinaltranslation of second lead screw (15460) causes concurrent translationof translatable member (15422) and articulation band (15342). Thus, inthe present version, second lead screw (15460) is operable to both pusharticulation band (15342) distally and pull articulation band (15342)proximally, depending on which direction housing (15430) is rotated.Other suitable relationships will be apparent to those of ordinary skillin the art in view of the teachings herein.

FIGS. 245A-245C show several of the above described componentsinteracting to bend articulation section (15330) to articulate endeffector (15240) in response to rotation of knob (15402) relative tohandle assembly (15220). It should be understood that in FIGS. 245A-245Cdepicts a side elevational view of handle assembly (15220) and a topplan view of shaft assembly (15230), including articulation section(15330). In FIG. 245A, articulation section (15330) is in asubstantially straight configuration. Then, housing (15430) is rotatedby rotation of articulation knob (15402). In particular, rotation ofarticulation knob (15402) is communicated to housing (15430) via meshingbevel gears (15410, 15438). The resulting rotation of housing (15430)which causes first lead screw (15450) to translate proximally and secondlead screw (15460) to advance distally. This proximal translation offirst lead screw (15450) pulls articulation band (15340) proximally viatranslatable member (15440), which causes articulation section (15330)to start bending as shown in FIG. 245B. This bending of articulationsection (15330) pulls articulation band (15342) distally. The distaladvancement of second lead screw (15460) in response to rotation ofhousing (15430) enables articulation band (15342) and translatablemember (15442) to advance distally. In some other versions, the distaladvancement of second lead screw (15460) actively drives translatablemember (15442) and articulation band (15342) distally. As the operatorcontinues rotating housing (15430) by rotating articulation knob(15402), the above described interactions continue in the same fashion,resulting in further bending of articulation section (15330) as shown inFIG. 245C.

It should be understood that, after reaching the articulation state inFIG. 245C by rotating knob (15402) in a first direction, rotation ofknob (15402) in a second (opposite) direction will cause articulationsection (15330) to return to the straight configuration shown in FIG.245A. As noted above, detent features (15224, 15412) may cooperate toprovide tactile feedback via knob (15402) to indicate that articulationsection (15330) has reached the straight configuration. Still furtherrotation of knob (15402) in that second direction will eventually resultin articulation section (15330) deflecting in a direction opposite tothat shown in FIGS. 245B-245C.

The angles of threading (15433, 15435, 15452, 15462) are configured suchthat articulation section (15330) will be effectively locked in anygiven articulated position, such that transverse loads on end effector(15240) will generally not bend articulation section (15330), due tofriction between threading (15433, 15435, 15452, 41562). In other words,articulation section (15330) will only change its configuration whenhousing (15430) is rotated via knob (15402). While the angles ofthreading may substantially prevent bending of articulation section(15330) in response to transverse loads on end effector (15240), theangles may still provide ready rotation of housing (15430) to translatelead screws (15450, 15460). By way of example only, the angles ofthreading (15433, 15435, 15452, 15462) may be approximately +/−2 degreesor approximately +/−3 degrees. Other suitable angles will be apparent tothose of ordinary skill in the art in view of the teachings herein. Itshould also be understood that threading (15433, 15435, 15452, 15462)may have a square or rectangular cross-section or any other suitableconfiguration.

In some instances, manufacturing inconsistencies may result inarticulation bands (15340, 15342) and/or translatable members (15440,15442) having slightly different lengths. In addition or in thealternative, there may be inherent manufacturing related inconsistenciesin the initial positioning of lead screws (15450, 15460) relative tohousing (15430) and/or other inconsistencies that might result inundesirable positioning/relationships of articulation bands (15340,15342) and/or translatable members (15440, 15442). Such inconsistenciesmay result in lost motion or slop in the operation of the articulationfeatures of instrument (15200). To address such issues, tensioner gears(not shown) may be incorporated into drive assembly (15420) to adjustthe longitudinal position of translatable members (15440, 15442)relative to lead screws (15450, 15460). Lead screws (15450, 15460) mayremain substantially stationary during such adjustments. Articulationsection (15330) may remain substantially straight during suchadjustments and may even be held substantially straight during suchadjustments.

In addition to or in lieu of the foregoing, drive assembly (15420) maybe configured and operable in accordance with at least some of theteachings of U.S. Pub. No. 2013/0023868, issued as U.S. Pat. No.9,545,253 on Jan. 17, 2017, entitled “Surgical Instrument with ContainedDual Helix Actuator Assembly,” published Jan. 24, 2013, the disclosureof which is incorporated by reference herein; in U.S. Pub. No.2012/0078243, issued as U.S. Pat. No. 9,877,720 on Jan. 30, 2018,entitled “Control Features for Articulating Surgical Device,” publishedMar. 29, 2012, the disclosure of which is incorporated by referenceherein; and in U.S. Pub. No. 2012/0078244, entitled “Control Featuresfor Articulating Surgical Device,” published Mar. 29, 2012, thedisclosure of which is incorporated by reference herein.

B. Exemplary Motorized Articulation Control Assembly and RigidizingMember

In some versions of instruments (10, 15200) it may be desirable toprovide motorized control of articulation section (130, 15330). This mayfurther promote single-handed use of the instrument, such that two handsare not required in order to control articulation section (130, 15300).

It may also be desirable to provide features that are configured toselectively provide rigidity to articulation sections (130, 15330). Forinstance, because of various factors such as manufacturing tolerances,design limitations, material limitations, and/or other factors, someversions of articulation sections (130, 15330) may be susceptible tosome “play” or other small movement of the articulation section despitebeing relatively fixed in a given position, such that articulationsections (130, 15330) are not entirely rigid. It may be desirable toreduce or eliminate such play in articulation sections (130, 15330),particularly when articulation sections (130, 15330) are in a straight,non-articulated configuration. Features may thus be provided toselectively rigidize articulation sections (130, 15330). Variousexamples of features that are configured to selectively provide rigidityto articulation sections (130, 15330) and/or to limit or preventinadvertent deflection of end effectors (15040, 15240) will be describedin greater detail below. Other examples will be apparent to those ofordinary skill in the art according to the teachings herein. It shouldbe understood that the examples of shaft assemblies and/or articulationsections described below may function substantially similar to shaftassemblies (15030, 15230) discussed above.

It should also be understood that articulation sections (130, 15330) maystill be at least somewhat rigid before being modified to include therigidizing features described below, such that the rigidizing featuresdescribed below actually just increase the rigidity of articulationsections (130, 15330) rather than introducing rigidity to otherwisenon-rigid articulation sections (130, 15330). For instance, articulationsections (130, 15330) in the absence of features as described below maybe rigid enough to substantially maintain a straight or articulatedconfiguration; yet may still provide “play” of about 1 mm or a fractionthereof such that the already existing rigidity of articulation sections(130, 15330) may be increased. Thus, terms such as “provide rigidity,”“providing rigidity,” “rigidize,” and “rigidizing,” etc. shall beunderstood to include just increasing rigidity that is already presentin some degree. The terms “provide rigidity,” “providing rigidity,”“rigidize,” and “rigidizing,” etc. should not be read as necessarilyrequiring articulation sections (130, 330) to completely lack rigiditybefore the rigidity is “provided.”

1. Overview

FIGS. 246-248 show an exemplary ultrasonic surgical instrument (15500)that is configured to be used in minimally invasive surgical procedures(e.g., via a trocar or other small diameter access port, etc.). As willbe described in greater detail below, instrument (15500) is operable tocut tissue and seal or weld tissue (e.g., a blood vessel, etc.)substantially simultaneously. Instrument (15500) of this examplecomprises a disposable assembly (15501) and a reusable assembly (15502).The distal portion of reusable assembly (15502) is configured toremovably receive the proximal portion of disposable assembly (15501),as seen in FIGS. 247-248, to form instrument (15500). By way of exampleonly, instrument (15500) may be configured and operable in accordancewith at least some of the teachings of U.S. patent application Ser. No.14/623,812, Published as U.S. Pub. No. 2015/0245850 on Sep. 3, 2015,entitled “Ultrasonic Surgical Instrument with Removable HandleAssembly,” filed Feb. 17, 2015, the disclosure of which is incorporatedby reference herein.

In an exemplary use, assemblies (15501, 15502) are coupled together toform instrument (15500) before a surgical procedure, the assembledinstrument (15500) is used to perform the surgical procedure, and thenassemblies (15501, 15502) are decoupled from each other for furtherprocessing. In some instances, after the surgical procedure is complete,disposable assembly (15501) is immediately disposed of while reusableassembly (15502) is sterilized and otherwise processed for re-use. Byway of example only, reusable assembly (15502) may be sterilized in aconventional relatively low temperature, relatively low pressure,hydrogen peroxide sterilization process. Alternatively, reusableassembly (15502) may be sterilized using any other suitable systems andtechniques (e.g., autoclave, etc.). In some versions, reusable assembly(15502) may be sterilized and reused approximately 100 times.Alternatively, reusable assembly (15502) may be subject to any othersuitable life cycle. For instance, reusable assembly (15502) may bedisposed of after a single use, if desired. While disposable assembly(15501) is referred to herein as being “disposable,” it should beunderstood that, in some instances, disposable assembly (15501) may alsobe sterilized and otherwise processed for re-use. By way of exampleonly, disposable assembly (15501) may be sterilized and reusedapproximately 2-30 times, using any suitable systems and techniques.Alternatively, disposable assembly (15501) may be subject to any othersuitable life cycle.

In some versions, disposable assembly (15501) and/or reusable assembly(15502) includes one or more features that are operable to track usageof the corresponding assembly (15501, 15502), and selectively restrictoperability of the corresponding assembly (15501, 15502) based on use.For instance, disposable assembly (15501) and/or reusable assembly(15502) may include one or more counting sensors and a control logic(e.g., microprocessor, etc.) that is in communication with the countingsensor(s). The counting sensor(s) may be able to detect the number oftimes the ultrasonic transducer of instrument (15500) is activated, thenumber of surgical procedures the corresponding assembly (15501, 15502)is used in, the number of trigger closures, and/or any other suitableconditions associated with use. The control logic may track data fromthe counting sensor(s) and compare the data to one or more thresholdvalues. When the control logic determines that one or more thresholdvalues have been exceeded, the control logic may execute a controlalgorithm to disable operability of one or more components in thecorresponding assembly (15501, 15502). In instances where the controllogic stores two or more threshold values (e.g., a first threshold fornumber of activations and a second threshold for number of surgicalprocedures, etc.), the control logic may disable operability of one ormore components in the corresponding assembly (15501, 15502) the firsttime one of those thresholds is exceeded, or on some other basis.

In versions where a control logic is operable to disable instrument(15500) based on the amount of use, the control logic may also determinewhether instrument (15500) is currently being used in a surgicalprocedure, and refrain from disabling instrument (15500) until thatparticular surgical procedure is complete. In other words, the controllogic may allow the operator to complete the current surgical procedurebut prevent instrument (15500) from being used in a subsequent surgicalprocedure. Various suitable forms that counters or other sensors maytake will be apparent to those of ordinary skill in the art in view ofthe teachings herein. Various suitable forms that a control logic maytake will also be apparent to those of ordinary skill in the art in viewof the teachings herein. Similarly, various suitable control algorithmsthat may be used to restrict usage of instrument (15500) will beapparent to those of ordinary skill in the art in view of the teachingsherein. Of course, some versions of instrument (15500) may simply omitfeatures that track and/or restrict the amount of usage of instrument(15500).

As shown in FIGS. 249-293C, disposable assembly (15501) of the presentexample comprises a body portion (15520), a shaft assembly (15530)extending distally from body portion (15520), and an end effector(15540) disposed at a distal end of shaft assembly (15530). Body portion(15520) of the present example comprises a housing (15522) whichincludes a button (15526). Button (15526) is operable just like button(15226) described above. Body portion (15520) also includes a trigger(15528) that is pivotable toward and away from a pistol grip (15524) ofreusable assembly (15502) to selectively actuate end effector (15540) asdescribed above and as described in one or more of the references citedherein. It should be understood, however, that various other suitableconfigurations may be used, including but not limited to a scissor gripconfiguration. End effector (15540) includes an ultrasonic blade (15560)and a pivoting clamp arm (15544). Clamp arm (15544) is coupled withtrigger (15528) such that clamp arm (15544) is pivotable towardultrasonic blade (15560) in response to pivoting of trigger (15528)toward pistol grip (15524); and such that clamp arm (15544) is pivotableaway from ultrasonic blade (15560) in response to pivoting of trigger(15528) away from pistol grip (15524). Various suitable ways in whichclamp arm (15544) may be coupled with trigger (15528) will be apparentto those of ordinary skill in the art in view of the teachings herein.In some versions, one or more resilient members are used to bias clamparm (15544) and/or trigger (15528) to the open position shown in FIGS.246-248. It should also be understood that clamp arm (15544) may beomitted if desired.

2. Exemplary End Effector and Acoustic Drivetrain

As discussed above, end effector (15540) of the present examplecomprises clamp arm (15544) and ultrasonic blade (15560). Clamp arm(15544) includes a clamp pad (15546) that is secured to the underside ofclamp arm (15544), facing ultrasonic blade (15560). Clamp pad (15546)may comprise PTFE and/or any other suitable material(s). Clamp arm(15544) is operable to selectively pivot toward and away from ultrasonicblade (15560) to selectively clamp tissue between clamp arm (15544) andblade (15560).

As with clamp arms (15044, 15244) discussed above, clamp arm (15544) ofthe present example is pivotally secured to a cable (15574). Cable(15574) is slidably disposed within an outer sheath (15532) of shaftassembly (15530) as shown in FIG. 252. Cable (15574) is operable totranslate longitudinally relative to an articulation section (15630) ofshaft assembly (15530) to selectively pivot clamp arm (15544) toward andaway from blade (15560). In particular, cable (15574) is coupled withtrigger (15528) such that cable (15574) translates proximally inresponse to pivoting of trigger (15528) toward pistol grip (15524), andsuch that clamp arm (15544) thereby pivots toward blade (15560) inresponse to pivoting of trigger (15528) toward pistol grip (15524). Inaddition, cable (15574) translates distally in response to pivoting oftrigger (15528) away from pistol grip (15524), such that clamp arm(15544) pivots away from blade (15560) in response to pivoting oftrigger (15528) away from pistol grip (15524). Clamp arm (15544) may bebiased toward the open position, such that (at least in some instances)the operator may effectively open clamp arm (15544) by releasing a gripon trigger (15528).

Blade (15560) of the present example is operable to vibrate atultrasonic frequencies in order to effectively cut through and sealtissue, particularly when the tissue is being compressed between clamppad (15546) and blade (15560). Blade (15560) is positioned at the distalend of an acoustic drivetrain. Acoustic waveguide (15580) comprises aflexible portion (15266). As with flexible portions (166, 15266) ofwaveguides (180, 15280) discussed above, flexible portion (15566) ofwaveguide (15580) includes a narrowed section (15564). Narrowed section(15564) is configured to allow flexible portion (15566) of waveguide(15580) to flex without significantly affecting the ability of flexibleportion (15566) of waveguide (15580) to transmit ultrasonic vibrations.By way of example only, narrowed section (15564) may be configured inaccordance with one or more teachings of U.S. Pub. No. 2014/0005701,issued as U.S. Pat. No. 9,393,037 on Jul. 19, 2016, and/or U.S. Pub. No.2014/0114334, issued as U.S. Pat. No. 9,095,367 on Aug. 4, 2015, thedisclosures of which are incorporated by reference herein. It should beunderstood that waveguide (15580) may be configured to amplifymechanical vibrations transmitted through waveguide (15580).Furthermore, waveguide (15580) may include features operable to controlthe gain of the longitudinal vibrations along waveguide (15580) and/orfeatures to tune waveguide (15580) to the resonant frequency of thesystem.

In the present example, the distal end of blade (15560) is located at aposition corresponding to an anti-node associated with resonantultrasonic vibrations communicated through flexible portion (15566) ofwaveguide (15580), in order to tune the acoustic assembly to a preferredresonant frequency f_(o) when the acoustic assembly is not loaded bytissue. When tissue is secured between blade (15560) and clamp pad(15546), the ultrasonic oscillation of blade (15560) may simultaneouslysever the tissue and denature the proteins in adjacent tissue cells,thereby providing a coagulative effect with relatively little thermalspread. In some versions, an electrical current may also be providedthrough blade (15560) and clamp arm (15544) to also cauterize thetissue.

3. Exemplary Shaft Assembly, Articulation Section, and RigidizingFeatures

Shaft assembly (15530) of the present example extends distally from bodyportion (15520). As best seen in FIGS. 251-252, shaft assembly (15530)includes distal outer sheath (15533) and a proximal outer sheath (15532)that enclose the drive features of clamp arm (15544) and theabove-described acoustic transmission features. Shaft assembly (15530)further includes an articulation section (15530), which is located at adistal portion of shaft assembly (15530), with end effector (15540)being located distal to articulation section (15630).

Articulation section (15630) of the present example is configured tooperate substantially similar to articulation sections (130, 15330)discussed above except for any differences discussed below. Inparticular, articulation section (15630) is operable to selectivelyposition end effector (15540) at various lateral deflection anglesrelative to a longitudinal axis defined by outer sheath (15532).Articulation section (15630) may take a variety of forms. By way ofexample only, articulation section (15630) may be configured inaccordance with one or more teachings of U.S. Pub. No. 2012/0078247,issued as U.S. Pat. No. 9,402,682 on Aug. 2, 2016, the disclosure ofwhich is incorporated by reference herein. As another merelyillustrative example, articulation section (15630) may be configured inaccordance with one or more teachings of U. S. Pub. No. 2014/0005701,issued as U.S. Pat. No. 9,393,037 on Jul. 19, 2016, and/or U. S. Pub.No. 2014/0114334, issued as U.S. Pat. No. 9,045,367 on Aug. 4, 2015, thedisclosures of which are incorporated by reference herein. Various othersuitable forms that articulation section (15630) may take will beapparent to those of ordinary skill in the art in view of the teachingsherein.

As shown in FIGS. 251-253, shaft assembly (15530) further comprises apair of articulation bands (15540, 15542) and a pair of translatablerods (15640, 15642). Articulation bands (15540, 15542) are configured tooperate substantially similar to articulation bands (140, 142, 15340,15342) discussed above, except for any differences discussed below. Forinstance, when articulation bands (15540, 15542) translatelongitudinally in an opposing fashion, this will cause articulationsection (15530) to bend, thereby laterally deflecting end effector(15540) away from the longitudinal axis of shaft assembly (15530) from astraight configuration as shown in FIG. 293A to an articulatedconfiguration as shown in FIGS. 293B and 293C. In particular, endeffector (15540) will be articulated toward the articulation band(15540, 15542) that is being pulled proximally. During sucharticulation, the other articulation band (15540, 15542) may be pulleddistally. Alternatively, the other articulation band (15540, 15542) maybe driven distally by an articulation control. Flexible acousticwaveguide (15566) is configured to effectively communicate ultrasonicvibrations from waveguide (15580) to blade (15560) even whenarticulation section (15630) is in an articulated state as shown inFIGS. 293B and 293C.

Translatable members (15640, 15642) are slidably disposed within theproximal portion of outer sheath (15532). Translatable members (15640,15642) extend longitudinally through the proximal portion of outersheath (15532) along opposite sides of outer sheath (15532) and adjacentan interior surface of outer sheath (15532). As best seen in FIG. 253,an elongate recess (15644) is formed in an exterior surface of a distalportion of each translatable member (15640, 15642). Elongate recesses(15644) are configured to receive a proximal portion of eacharticulation band (15540, 15542). Each translatable member (15640,15642) further includes a pin (15643) projecting outwardly from aninterior surface of each elongate recess (15644). An opening (15641)formed in a proximal end of each articulation band (15640, 15642) isconfigured to receive a respective pin (15643) of translatable members(15640, 15642). Pins (15643) and openings (15641) thus function tomechanically couple translatable members (15640, 15642) witharticulation bands (15540, 542) such that longitudinal translation oftranslatable member (15640) causes concurrent longitudinal translationof articulation band (15540), and such that longitudinal translation oftranslatable member (15642) causes concurrent longitudinal translationof articulation band (15542).

When translatable members (15640, 15642) and articulation bands (15540,15542) are translated longitudinally in an opposing fashion, a moment iscreated and applied to a distal end of distal outer sheath (15533) in amanner similar to that described above with respect to articulationsection (130). This causes articulation section (15630) and narrowedsection (15564) of flexible portion (15566) of waveguide (15580) toarticulate, without transferring axial forces in articulation bands(15540, 15542) to waveguide (15580) as described above. It should beunderstood that one articulation band (15540, 15542) may be activelydriven distally while the other articulation band (15540, 15542) ispassively permitted to retract proximally. As another merelyillustrative example, one articulation band (15340, 15342) may beactively driven proximally while the other articulation band (15540,15542) is passively permitted to advance distally. As yet another merelyillustrative example, one articulation band (15540, 15542) may beactively driven distally while the other articulation band (15540,15542) is actively driven proximally. Various suitable ways in whicharticulation bands (15540, 15542) may be driven will be apparent tothose of ordinary skill in the art in view of the teachings herein.

As shown in FIGS. 251-252, 269-271, 288-290, and 292A-292B, shaftassembly (15530) further comprises a rod member (15740) slidablydisposed within the proximal portion of outer sheath (15532). As will bedescribed in more detail below, rod member (15740) is operable totranslate between a proximal longitudinal position (FIG. 292B) in whichrod member (15740) is positioned proximally of articulation section(15630), and a distal longitudinal position (FIG. 292A) in which rodmember (15740) extends through articulation section (15630) and therebyprevents rigidizes articulation section (15740).

As shown in FIGS. 249-250, a rotation knob (15531) is secured to aproximal portion of proximal outer sheath (15532). Rotation knob (15531)is rotatable relative to housing (15522), such that shaft assembly(15530) is rotatable about the longitudinal axis defined by outer sheath(15532), relative to body portion (15520). Such rotation may providerotation of end effector (15540), articulation section (15630), andshaft assembly (15530) unitarily. Of course, rotatable features maysimply be omitted if desired.

4. Exemplary Articulation Control Assembly

FIGS. 254-293C show the components and operation of an articulationcontrol assembly (15700) that is configured to provide control forarticulation of articulation section (15630). Articulation controlassembly (15700) of this example comprises a motor (15702) and a bevelgear (15704). Motor (15702) is secured within an upper portion ofhousing (15522) of body portion (15520). As best seen in FIG. 256, motor(15702) is oriented obliquely relative to shaft assembly (15530) suchthat an axle (15703) of motor (15702) is configured to rotate about anaxis that is oblique to the longitudinal axis defined by shaft assembly(15530). Motor (15702) comprises a button (15706) that is configured toselectively cause motor (15702) to rotate axle (15703) is a firstdirection and in a second direction. As best seen in FIG. 256, bevelgear (15704) is mechanically coupled with axle (15703) of motor (15702)such that rotation of axle (15703) causes concurrent rotation of bevelgear (15704). Bevel gear (15704) includes a plurality of teeth (15710).As will be described in more detail below, rotation of bevel gear(15704) by motor (15702) will cause articulation of articulation section(15630). In some alternative versions, motor (15702) and bevel gear(15704) are replaced with a manually rotatable knob and bevel gearsimilar to knob (15402) and bevel gear (15404) described above.

As best seen in FIG. 259, articulation control assembly (15700) furthercomprises a drive assembly (15720). Drive assembly (15720) is secured toa proximal portion of proximal outer sheath (15532). Drive assembly(15720) is further rotatably disposed within rotation knob (15531) suchthat rotation knob (15531) is configured to rotate independently aboutdrive assembly (15720) to thereby cause rotation of shaft assembly(15530) without causing rotation of drive assembly (15720).

As shown in FIGS. 259A-260, drive assembly (15720) comprises a proximalhousing (15730), a distal housing (15735), a plurality of lead screws(15750, 15760, 15770), and a cylindrical guide (15780). Distal housing(15735) and proximal housing (15730) are coupled to one another via aplurality of interlocking tabs (15769) and slots (15767) such thatrotation of proximal housing (15730) causes concurrent rotation ofdistal housing (15735). Proximal housing (15730) is also coupled with anoutput flange (15936) of a gear reduction assembly (15900) throughengagement between tabs (15769) and slots (15938), as will be describedin greater detail below, such that rotation of output flange (15936)causes concurrent rotation of proximal housing (15730). Distal housing(15735), proximal housing (15730), and gear reduction assembly (15900)substantially encompass the internal components of drive assembly(15720) as will be described in more detail below.

FIGS. 259B-259J show gear reduction assembly (15900) in greater detail.Gear reduction (15900) assembly of the present example comprises a bevelgear (15910), a fixed spline member (15920), and a flex spline member(15930). As best seen in FIG. 259C, bevel gear (15910), fixed splinemember (15920), and flex spline member (15930) are all coaxially alignedwith each other and provide clearance for waveguide (15580) and theproximal portions of the rest of shaft assembly (15530) to be coaxiallydisposed therethrough. As best seen in FIGS. 259D-259E, bevel gear(15910) comprises an array of bevel gear teeth (15912) and an outputshaft (15914). Bevel gear teeth (15912) are configured and positioned tomesh with teeth (15710) of bevel gear (15704) such that rotation ofbevel gear (15704) causes concurrent rotation of bevel gear (15910). Inother words, activation of motor (15702) will cause rotation of bevelgear (15910). As best seen in FIG. 259E, output shaft (15914) has anouter surface with an elliptical profile. This allows output shaft(15914) to act as a wave generator within gear reduction assembly(15900) as will be described in greater detail below.

FIGS. 259F-259G show fixed spline member (15920) in greater detail.Fixed spline member (15920) comprises a rigid cylindraceous body (15922)with an array of internal teeth (15924) and an outwardly extendingannular flange (15926). Flange (15926) is fixedly secured to housing(15522) of body portion (15520) such that fixed spline member (15920) isconfigured to remain stationary within body portion (15520). FIGS.259H-259I show flex spline member (15930) in greater detail. Flex splinemember (15930) comprises a set external teeth (15932) positioned at aproximal end of a cylindraceous body (15934). Body (15934) is configuredto deform radially outwardly yet is also configured to rigidly transferrotation along the length of body (15934). Various suitable materialsand configurations that may be used to provide such radial flexingcombined with rigid torque transfer will be apparent to those ofordinary skill in the art in view of the teachings herein. Output flange(15936) is positioned at the distal end of body (15934). As noted above,output flange (15936) includes an array of slots (15938) that receivetabs (15769) of proximal housing (15730), such that rotation of flexspline member (15930) causes concurrent rotation of proximal housing(15730).

As best seen in FIG. 259J, teeth (15932) of flex spline member (15930)are configured and positioned to mesh with teeth (15924) of rigid splinemember (15920). At any given moment, only some of teeth (15932) areengaged with teeth (15924). By way of example only, rigid spline member(15930) may be configured to have at least two more teeth (15924) thanflex spline member (15930). As also best seen in FIG. 259J, theelliptical outer surface of output shaft (15914) of bevel gear (15910)bears against the inner surface (15935) of body (15934) of flex splinemember (15930). In particular, the elliptical outer surface of outputshaft (15914) bears against inner surface (15935) at the antipodalpoints of the major axis of the elliptical outer surface of output shaft(15914). Thus, as bevel gear (15910) is rotated, the points of contactbetween bevel gear (15910) and flex spline member (15930) orbit aboutthe central longitudinal axis of gear reduction assembly (15900). Thiscauses teeth (15932) to engage teeth (15924) in orbital paths about thecentral longitudinal axis of gear reduction assembly (15900), with body(15934) flexibly deforming to provide this engagement between teeth(15924, 15932). Rigid spline member (15920) remains stationary whileflex spline member (15930) rotates during such engagement. The rotationof flex spline member (15930) provides rotation of proximal housing(15730) as noted above. Proximal housing (15730) thus rotates inresponse to rotation of bevel gear (15910).

It should be understood from the foregoing that activation of motor(15702) will cause rotation of housings (15730, 15735) via gearreduction assembly (15900). It should also be understood that gearreduction assembly (15900) provides a strain wave gearing system orharmonic drive system. By way of example only, gear reduction assembly(15900) may be further configured and operable in accordance with atleast some of the teachings of U.S. Pat. No. 2,906,143, entitled “StrainWave Gearing,” issued Sep. 29, 1959, the disclosure of which isincorporated by reference herein. In the present example, gear reductionassembly (15900) provides a gear reduction of approximately 25:1.Alternatively, any other suitable gear reduction may be provided.

As shown in FIGS. 262-265, proximal housing (15730) includes internalthreading (15733) formed in an interior surface of proximal housing(15730). As shown in FIGS. 272-276, distal housing (15735) includesproximal internal threading (15910) formed in an interior surface ofdistal housing (15735); and distal internal threading (15737) formed inthe interior surface of distal housing (15735). Threadings (15736,15737) have opposing pitch angles or orientations in this example. Inother words, the pitch orientation of threading (15910) is opposite tothe pitch orientation of threading (15737). As should be understood bycomparing FIGS. 264, 265, 275, and 276, a proximal portion (15733A) ofthreading (15733) of proximal housing (15730) has a greater pitch anglethan a distal portion (15733B) of threading (15733) as well asthreadings (15736, 15737) of distal housing (15735). As will bedescribed in more detail below, this difference in pitch angles iscauses a variance in the speed of longitudinal translation of rod member(15740).

As shown in FIGS. 266-268, a first lead screw (15750) includes a pair ofwedge-shaped projections (15751) extending outwardly from radiallyopposing sides of first lead screw (15750). First lead screw (15750)further includes a discrete exterior thread (15754) projecting outwardlyfrom an exterior surface of projection (15751). Thread (15754) isconfigured to engage with threading (15733) of proximal housing (15730).The pitch angle of thread (15754) complements the pitch angle ofthreading (15733). As will be described in greater detail below,articulation control assembly (15700) is configured to permit lead screw(15750) to slide longitudinally within drive assembly (15720) yetprevent lead screw (15750) from rotating within drive assembly (15720).It should therefore be understood that rotation of proximal housing(15730) in a first direction will drive lead screw (15750) proximally;and rotation of proximal housing (15730) in a second direction willdrive lead screw (15750) distally.

As shown in FIGS. 277-279, a second lead screw (15760) includes a pairof semi-cylindrical flanges (15761) extending from radially opposingsides of an annular body (15763). Second lead screw (15760) furtherincludes a discrete exterior thread (15762) projecting outwardly from anexterior surface of flange (15761). Thread (15762) is configured toengage with proximal internal threading (15910) of distal housing(15735). As shown in FIGS. 280-282, a third lead screw (15770) includesa pair of semi-cylindrical flanges (15771) extending from radiallyopposing sides of an annular body (15773). Second lead screw (15770)further includes a discrete exterior thread (15772) projecting outwardlyfrom an exterior surface of flange (15771). Thread (15772) is configuredto engage with distal internal threading (15737) of distal housing(15735). The pitch angle of thread (15762) complements the pitch angleof threading (15910); while the pitch angle of thread (15772)complements the pitch angle of threading (15737). As will be describedin greater detail below, articulation control assembly (15700) isconfigured to permit lead screws (15760, 15770) to slide longitudinallywithin drive assembly (15720) yet prevent lead screws (15760, 15770)from rotating within drive assembly (15720). It should therefore beunderstood that, due to the opposing pitch angles of threading (15736,15737), rotation of distal housing (15735) in a first direction willdrive lead screw (15760) distally while simultaneously driving leadscrew (15770) proximally; and rotation of distal housing (15735) in asecond direction will drive lead screw (15760) proximally whilesimultaneously driving lead screw (15770) distally.

As best seen in FIG. 278, a pair of semi-circular gaps (15765) aredefined between an interior surface of each flange (15761) and anexterior surface of annular body (15763) of second lead screw (15760).As best seen in FIG. 281, a pair of semi-circular gaps (15775) aredefined between an interior surface of each flange (15771) and anexterior surface of annular body (15773) of second lead screw (15770).As best seen in FIG. 260, cylindrical guide (15780) is positioned withinhousings (15730, 15735) about the proximal portion of outer sheath(15532). As shown in FIG. 261, a proximal end of cylindrical guide(15780) comprises a structural frame (15782). Structural frame (15782)of cylindrical guide (15780) is configured to be fixedly secured withinthe interior of housing (15522) of body portion (15520) such thatcylindrical guide (15780) is configured to remain stationary within bodyportion (15520).

Cylindrical guide (15780) comprises a plurality of longitudinal slots(15784) formed by a plurality of elongate sidewalls (15786) ofcylindrical guide (15780). In particular, a first pair of longitudinalslots (15784A) is formed in radially opposing sides of a sidewall ofcylindrical guide (15780), and a second pair of longitudinal slots(15784B) is formed in radially opposing sides of a sidewall ofcylindrical guide (15780). As shown in FIG. 243, projections (15751) offirst lead screw (15750) are configured to be received withinlongitudinal slots (15784A) of cylindrical guide (15780) such that firstlead screw (15750) is slidably disposed along longitudinal slots(15784A). Thus, lead screw (15750) is operable to translate withinproximal housing (15730) but is prevented from rotating within proximalhousing (15730).

As best seen in FIGS. 288 and 289, longitudinal sidewalls (15786) ofcylindrical guide (15780) are configured to be received within gaps(15765) of second lead screw (15760) such that lead screw (15760) isslidably disposed along cylindrical guide (15780) within distal housing(15735). As best seen in FIG. 290, longitudinal sidewalls (15786) ofcylindrical guide (15780) are configured to be received within gaps(15775) of third lead screw (15770) such that lead screw (15770) isslidably disposed along cylindrical guide (15780) within distal housing(15735). Thus, lead screws (15760, 15770) are operable to translatewithin distal housing (15735) but are prevented from rotating withindistal housing (15735).

As shown in FIGS. 269 and 270, first lead screw (15750) is secured to aproximal end of rod member (15740) via a tensioner (15756). As shown inFIGS. 283-286, tensioner (15756) includes a first threaded member(15756A) and a second threaded member (15756B). Threaded members(15756A, 15756B) threadably engage one another such that a longitudinalposition of threaded members (15756A, 15756B) relative to one anothermay be changed by rotation of first threaded member (15756A) and/orsecond threaded member (15756B). An exterior surface of first threadedmember (15756A) of tensioner (15756) is secured to an interior surfaceof a through-bore (15755) of first lead screw (15750) such thatlongitudinal translation of first lead screw (15750) causes concurrentlongitudinal translation of tensioner (15756). As best seen in FIG. 270,a key (15757) of second threaded member (15756B) of tensioner (15756) ispositioned within a mating slot (15747) formed in the proximal end ofrod member (15740) such that longitudinal translation of first leadscrew (15750) causes current longitudinal translation of rod member(15740). Thus, in the present version, first lead screw (15750) isoperable to both push rod member (15740) distally and pull rod member(15740) proximally, depending on which direction proximal housing(15730) is rotated. Other suitable relationships will be apparent tothose of ordinary skill in the art in view of the teachings herein.

As shown in FIG. 287, a proximal end of each translatable rod (15640,15642) includes a slot (15648, 15649) formed therein. As shown in FIG.288, second lead screw (15760) is secured to a proximal end oftranslatable rod (15642) via a tensioner (15756). An exterior surface ofa first threaded member (15756A) of tensioner (15756) is secured to aninterior surface of annular body (15763) of second lead screw (15760)such that longitudinal translation of second lead screw (15760) causesconcurrent longitudinal translation of tensioner (15756). A key (15757)of second threaded member (15756B) of tensioner (15756) is positionedwithin mating slot (15648) of translatable rod (15642) such thatlongitudinal translation of second lead screw (15760) causes currenttranslation of translatable rod (15642). Thus, in the present version,second lead screw (15760) is operable to both push translatable rod(15642) distally and pull translatable rod (15642) proximally, dependingon which direction distal housing (15735) is rotated. Becausetranslatable member (15642) is mechanically coupled with articulationband (15542), it should be understood that second lead screw (15760) isoperable to both push articulation band (15542) distally and pullarticulation band (15542) proximally, depending on which directiondistal housing (15735) is rotated. Other suitable relationships will beapparent to those of ordinary skill in the art in view of the teachingsherein.

As shown in FIG. 290, third lead screw (15770) is secured to a proximalend of translatable rod (15640) via a tensioner (15756). An exteriorsurface of a first threaded member (15756A) of tensioner (15756) issecured to an interior surface of annular body (15773) of third leadscrew (15770) such that longitudinal translation of third lead screw(15770) causes concurrent longitudinal translation of tensioner (15756).A key (15757) of second threaded member (15756B) of tensioner (15756) ispositioned within mating slot (15649) of translatable rod (15640) suchthat longitudinal translation of third lead screw (15770) causes currenttranslation of translatable rod (15640). Thus, in the present version,third lead screw (15770) is operable to both push translatable rod(15640) distally and pull translatable rod (15640) proximally, dependingon which direction distal housing (15735) is rotated. Becausetranslatable member (15640) are mechanically coupled with articulationband (15540), it should be understood that second lead screw (15760) isoperable to both push articulation band (15540) distally and pullarticulation band (15540) proximally, depending on which directiondistal housing (15735) is rotated. Other suitable relationships will beapparent to those of ordinary skill in the art in view of the teachingsherein.

FIGS. 291A-293C show several of the above described componentsinteracting to bend articulation section (15630) to articulate endeffector (15540). FIGS. 291A, 292A, and 293A correspond to one another.In FIG. 292A, rod member (15740) is in the distal longitudinal positionand thereby rigidizes articulation section (15730). In FIG. 293A,articulation section (15630) is in a substantially straightconfiguration. Then, housings (15730, 15735) are rotated by motor(15702) via gear reduction assembly (15900). The rotation of housings(15730, 15735) causes first lead screw (15750) to translate proximallywithin proximal housing (15730), second lead screw (15760) to translatedistally within distal housing (15735), and third lead screw (15770) toadvance proximally within distal housing (15735). This proximaltranslation of first lead screw (15750) is caused by rotation of firstlead screw (15750) within proximal portion (15733A) of threading(15733). As discussed above, the greater pitch angle of proximal portion(15733A) causes a greater rate of translation of first lead screw(15750) as compared with the translation rate of lead screws (15760,15770), as will be understood by comparing FIGS. 291A-291C. The proximaltranslation of first lead screw (15750) pulls rod member (15740)proximally in to the proximal longitudinal position as shown in FIG.292B.

The proximal translation of third lead screw (15770) pulls articulationband (15540) proximally via translatable rod (15640), which causesarticulation section (15630) to start bending as shown in FIG. 293B.This bending of articulation section (15630) pulls articulation band(15542) distally. The distal advancement of second lead screw (15760) inresponse to rotation of distal housing (15735) enables articulation band(15542) and translatable rod (15642) to advance distally. In some otherversions, the distal advancement of second lead screw (15760) activelydrives translatable rod (15642) and articulation band (15542) distally.As the operator continues rotating housings (15730, 15735) via motor(15702) and gear reduction assembly (15900), the above describedinteractions continue in the same fashion, resulting in further bendingof articulation section (15630) as shown in FIG. 293C. It should beunderstood that rotating housings (15730, 15735) in the oppositedirection will cause articulation section (15630) return to the straightconfiguration shown in FIG. 293A; and rod member (15740) to return tothe distal longitudinal position to thereby rigidize the straightenedarticulation section (15730).

The angles of threading (15733, 15736, 15737, 15754, 15762, 15772) areconfigured such that articulation section (15630) will be effectivelylocked in any given articulated position, such that transverse loads onend effector (15540) will generally not bend articulation section(15630), due to friction between threading (15733, 15736, 15737, 15754,15762, 15772). In other words, articulation section (15630) will onlychange its configuration when housings (15730, 15735) are rotated. Whilethe angles of threading may substantially prevent bending ofarticulation section (15630) in response to transverse loads on endeffector (15540), the angles may still provide ready rotation ofhousings (15730, 15735) to translate lead screws (15750, 15760, 15770).By way of example only, the angles of threading (15733, 15736, 15737,15754, 15762, 15772) may be approximately +/−2 degrees or approximately+/−3 degrees. Other suitable angles will be apparent to those ofordinary skill in the art in view of the teachings herein. It shouldalso be understood that threading (15733, 15736, 15737, 15754, 15762,15772) may have a square or rectangular cross-section or any othersuitable configuration.

In some versions, housings (15730, 15735) include a visual indicatorthat is associated with articulation section (15630) being in asubstantially straight configuration. Such a visual indicator may alignwith a corresponding visual indicator on rotation knob (15531) and/orbody (15822) of body portion (15520). Thus, when an operator has rotatedhousings (15730, 15735) to make articulation section (15630) approach asubstantially straight configuration, the operator may observe suchindicators to confirm whether articulation section (15630) has in factreached a substantially straight configuration. By way of example only,this may be done right before instrument (15500) is withdrawn from atrocar to reduce the likelihood of articulation section (15630) snaggingon a distal edge of the trocar. Of course, such indicators are merelyoptional.

FIGS. 294-298A show components of an exemplary alternative shaftassembly (15830) comprising an elongate tube member (15850) and atubular guide member (15860) that may be readily incorporated intoinstrument (10, 15200) in order to selectively rigidize articulationsection (130, 15330) when articulation section (130, 15330) is in astraight, non-articulated configuration. Tube member (15850) and guidemember (15860) may also be incorporated into instrument (15500) as asubstitute for rod member (15740) and associated components toselectively rigidize articulation section (15630) when articulationsection (15630) is in a straight, non-articulated configuration. In thepresent example, tube member (15850) and guide member (15860) are shownas selectively rigidizing an articulation section (15831), which mayotherwise be configured and operable just like articulation sections(130, 15330, 15630) described above.

Elongate tube member (15850) of the present example comprises asemi-circular tongue (15852) extending proximally from a proximal end ofelongate tube member (15850). As best seen in FIG. 295, tongue (15852)includes a pawl (15854) projecting inwardly and downwardly from aninterior surface of tongue (15852). As will be described in more detailbelow, elongate tube member (15850) is longitudinally translatable alonga length of shaft assembly (15830) between a distal longitudinalposition (FIGS. 297A and 298A) and a proximal longitudinal position(FIGS. 297C and 298C). In the distal position, elongate tube member(15850) is positioned about articulation section (15831) to therebyrigidize articulation section (15831). In the proximal position,elongate tube member (15850) is located proximally of articulationsection (15831) and thereby permits articulation of articulation section(15831). Elongate tube member (15850) of the present example isresiliently biased distally toward the distal longitudinal position.Various suitable ways in which elongate tube member (15850) may bebiased distally toward the distal longitudinal position will be apparentto those of ordinary skill in the art in view of the teachings herein.

Elongate tube member (15850) is configured to slidably and rotatablyreceive tubular guide member (15860) such that elongate tube member(15850) is operable to translate along a length of tubular guide member(15860) and such that tubular guide member (15860) is operable to rotatewithin elongate tube member (15850). However, while elongate tube member(15850) is configured to translate along a length of tubular guidemember (15860), elongate tube member (15850) is not configured to rotateabout tubular guide member (15860). In other words, elongate tube member(15850) is configured to remain in a single rotational position. Asshown in FIG. 296, tubular guide member (15860) includes an oval-shapedcam channel (15862) that is formed in a sidewall of tubular guide member(15860). Cam channel (15862) is oriented obliquely relative to thelongitudinal axis of tubular guide member (15860). Cam channel (15862)is configured to slidably receive pawl (15854) of elongate tube member(15850). As will be described in more detail below, pawl (15854) servesas a cam follower such that rotation of tubular guide member (15860)within elongate tube member (15850) causes translation of elongate tubemember (15850) as pawl (15854) translates within cam channel (15862) oftubular guide member (15860). As best seen in FIG. 296, a proximalportion (15862A) of cam channel (15862) comprises a detent (15864)formed in distal interior surface of cam channel (15862). As will bedescribed in more detail below, detent (15864) is configured to receivepawl (15854) to selectively maintain the position of pawl (15854) withinoval-shaped cam channel (15862).

FIGS. 297A-298C show several of the above described componentsinteracting to provide rigidity to articulation section (15831) and/orto prevent inadvertent deflection of end effector (15840) relative toouter sheath (15832). In FIGS. 297A and 298A, articulation section(15831) is in a substantially straight configuration and elongate tubemember (15850) covers articulation section (15831), thereby rigidizingarticulation section (15831). Then, tubular guide member (15860) isrotated about the longitudinal axis of shaft assembly (15830), whichcauses elongate tube member (15850) to translate proximally as pawl(15854) travels along cam channel (15862) as shown in FIG. 297B. Thisproximal translation of elongate tube member (15850) exposes a portionof articulation section (15831) as shown in FIG. 298B. As the operatorcontinues rotating tubular guide member (15860) about the longitudinalaxis of shaft assembly (15830) as shown in FIG. 297C, the abovedescribed interactions continue in the same fashion, resulting infurther proximal translation of elongate tube member (15850) due toengagement of pawl (15854) in cam channel (15862) until pawl (15854)engages detent (15864). As shown in FIG. 298C, this further proximaltranslation of elongate tube member (15850) completely exposesarticulation section (15831) such that articulation section (15831) maybe articulated. It should be understood that further rotation of tubularguide member (15860) in the same direction (15 or reversal of rotationof tubular guide member (15860)) will cause distal translation ofelongate tube member (15850) back to the distal longitudinal positionshown in FIGS. 297A and 298A due to engagement of pawl (15854) in camchannel (15862).

It should also be understood that the receipt of pawl (15854) in detent(15864) may provide the operator with tactile feedback indicating thatelongate tube member (15850) has reached the fully proximal position.Cooperation between pawl (15854) and detent (15864) may also providesome degree of resistance to inadvertent rotation of tubular guidemember (15860), thereby providing some degree of resistance to distaltranslation of elongate tube member (15850). Such resistance may beparticularly desirable in versions where elongate tube member (15850) isresiliently biased toward the distal position.

Tubular guide member (15860) may be actuated in various ways. Forinstance, at least a portion of tubular guide member (15860) may beexposed such that the operator may directly grasp tubular guide member(15860) to rotate tubular guide member (15860). As another merelyillustrative example, tubular guide member (15860) may include a knob orother user input feature that the operator may grasp or otherwisemanipulate to rotate tubular guide member (15860). As yet another merelyillustrative example, tubular guide member (15860) may be operativelycoupled with an articulation control assembly such as articulationcontrol assembly (100, 15400, 15700). In some such versions, thearticulation control assembly may automatically actuate tubular guidemember (15860) to drive elongate tube member (15850) to the distalposition when articulation section (15830) reaches the straight,non-articulated configuration. The articulation control assembly mayalso automatically actuate tubular guide member (15860) to driveelongate tube member (15850) to the proximal position when the operatoractuates the articulation control assembly to drive articulation section(15830) toward an articulated configuration. Elongate tube member(15850) may thus be actuated in a manner similar to rod member (15740)described above. Still other suitable ways in which elongate tube member(15850) and/or tubular guide member (15860) may be actuated will beapparent to those of ordinary skill in the art in view of the teachingsherein.

XVII. MISCELLANEOUS

The above teachings may be readily combined with the teachings of eachof the following: U.S. patent application Ser. No. 14/688,692, entitled“Ultrasonic Surgical Instrument with End Effector Having RestrictedArticulation,” filed on Apr. 16, 2015, published as Pub. No.2015/0320438 on Nov. 12, 2015, the disclosure of which is incorporatedby reference herein; U.S. patent application Ser. No. 14/688,234,entitled “Ultrasonic Surgical Instrument with Articulation Joint HavingPlurality of Locking Positions,” filed on Apr. 16, 2015, published asPub. No. 2016/0302817 on Oct. 20, 2016, the disclosure of which isincorporated by reference herein; U.S. patent application Ser. No.14/688,005 entitled “Ultrasonic Surgical Instrument with Rotatable ShaftHaving Plurality of Locking Positions,” filed on Apr. 16, 2015, issuedas U.S. Pat. No. 10,111,698 on Oct. 30, 2018, the disclosure of which isincorporated by reference herein; U.S. patent application Ser. No.14/688,424, entitled “Ultrasonic Surgical Instrument with ArticulationJoint Having Integral Stiffening Members,” filed on Apr. 16, 2015,issued as U.S. Pat. No. 10,029,125 Jul. 24, 2018, the disclosure ofwhich is incorporated by reference herein; U.S. patent application Ser.No. 14/688,458, entitled “Ultrasonic Surgical Instrument with RigidizingArticulation Drive Members,” filed on Apr. 16, 2015, issued as U.S. Pat.No. 10,034,683 on Jul. 31, 2018, the disclosure of which is incorporatedby reference herein; U.S. patent application Ser. No. 14/688,497,entitled “Ultrasonic Surgical Instrument with Movable RigidizingMember,” filed on Apr. 16, 2015, published as U.S. Pub. No. 2016/0302818on Oct. 20, 2016, the disclosure of which is incorporated by referenceherein; U.S. patent application Ser. No. 14/688,542 entitled “UltrasonicSurgical Instrument with Articulating End Effector having a CurvedBlade,” filed on Apr. 16, 2015, published as Pub. No. 2016/0302819 onOct. 20, 2016, the disclosure of which is incorporated by referenceherein; and U.S. patent application Ser. No. 14/688,633 entitled“Ultrasonic Surgical Instrument with Opposing Thread Drive for EndEffector Articulation,” filed on Apr. 16, 2015, published as Pub. No.2016/0302820 on Oct. 20, 2016, the disclosure of which is incorporatedby reference herein.

It should be understood that any of the versions of instrumentsdescribed herein may include various other features in addition to or inlieu of those described above. By way of example only, any of theinstruments described herein may also include one or more of the variousfeatures disclosed in any of the various references that areincorporated by reference herein. It should also be understood that theteachings herein may be readily applied to any of the instrumentsdescribed in any of the other references cited herein, such that theteachings herein may be readily combined with the teachings of any ofthe references cited herein in numerous ways. Moreover, those ofordinary skill in the art will recognize that various teachings hereinmay be readily applied to electrosurgical instruments, staplinginstruments, and other kinds of surgical instruments. Other types ofinstruments into which the teachings herein may be incorporated will beapparent to those of ordinary skill in the art.

It should be appreciated that any patent, publication, or otherdisclosure material, in whole or in part, that is said to beincorporated by reference herein is incorporated herein only to theextent that the incorporated material does not conflict with existingdefinitions, statements, or other disclosure material set forth in thisdisclosure. As such, and to the extent necessary, the disclosure asexplicitly set forth herein supersedes any conflicting materialincorporated herein by reference. Any material, or portion thereof, thatis said to be incorporated by reference herein, but which conflicts withexisting definitions, statements, or other disclosure material set forthherein will only be incorporated to the extent that no conflict arisesbetween that incorporated material and the existing disclosure material.

Versions of the devices described above may have application inconventional medical treatments and procedures conducted by a medicalprofessional, as well as application in robotic-assisted medicaltreatments and procedures. By way of example only, various teachingsherein may be readily incorporated into a robotic surgical system suchas the DAVINCI™ system by Intuitive Surgical, Inc., of Sunnyvale, Calif.Similarly, those of ordinary skill in the art will recognize thatvarious teachings herein may be readily combined with various teachingsof U.S. Pat. No. 6,783,524, entitled “Robotic Surgical Tool withUltrasound Cauterizing and Cutting Instrument,” published Aug. 31, 2004,the disclosure of which is incorporated by reference herein.

Versions described above may be designed to be disposed of after asingle use, or they can be designed to be used multiple times. Versionsmay, in either or both cases, be reconditioned for reuse after at leastone use. Reconditioning may include any combination of the steps ofdisassembly of the device, followed by cleaning or replacement ofparticular pieces, and subsequent reassembly. In particular, someversions of the device may be disassembled, and any number of theparticular pieces or parts of the device may be selectively replaced orremoved in any combination. Upon cleaning and/or replacement ofparticular parts, some versions of the device may be reassembled forsubsequent use either at a reconditioning facility, or by a userimmediately prior to a procedure. Those skilled in the art willappreciate that reconditioning of a device may utilize a variety oftechniques for disassembly, cleaning/replacement, and reassembly. Use ofsuch techniques, and the resulting reconditioned device, are all withinthe scope of the present application.

By way of example only, versions described herein may be sterilizedbefore and/or after a procedure. In one sterilization technique, thedevice is placed in a closed and sealed container, such as a plastic orTYVEK bag. The container and device may then be placed in a field ofradiation that can penetrate the container, such as gamma radiation,x-rays, or high-energy electrons. The radiation may kill bacteria on thedevice and in the container. The sterilized device may then be stored inthe sterile container for later use. A device may also be sterilizedusing any other technique known in the art, including but not limited tobeta or gamma radiation, ethylene oxide, or steam.

Having shown and described various embodiments of the present invention,further adaptations of the methods and systems described herein may beaccomplished by appropriate modifications by one of ordinary skill inthe art without departing from the scope of the present invention.Several of such potential modifications have been mentioned, and otherswill be apparent to those skilled in the art. For instance, theexamples, embodiments, geometries, materials, dimensions, ratios, steps,and the like discussed above are illustrative and are not required.Accordingly, the scope of the present invention should be considered interms of the following claims and is understood not to be limited to thedetails of structure and operation shown and described in thespecification and drawings.

We claim:
 1. A method of operating an apparatus, the apparatus comprising: (a) a shaft, wherein the shaft defines a longitudinal axis; (b) an acoustic waveguide, wherein the waveguide comprises a flexible portion, wherein the flexible portion comprises a narrowed section longitudinally interposed between a pair of enlarged portions, wherein the narrowed section of the acoustic waveguide comprises a single piece of material that is configured to bend and communicate ultrasonic vibrations while bent, wherein the enlarged portions are longitudinally spaced apart from each other; (c) an articulation section coupled with the shaft, wherein the articulation section is associated with the flexible portion of the waveguide, wherein the articulation section further comprises: (i) a first member, and (ii) a second member, wherein the second member is longitudinally translatable relative to the first member, wherein the first and second members are laterally offset from the narrowed section by the enlarged portions; (d) an end effector comprising: (i) an ultrasonic blade in acoustic communication with the waveguide, and (ii) a clamp arm, wherein the clamp arm is coupled with the first member and the second member; and (e) an articulation drive assembly operable to drive articulation of the articulation section to thereby deflect the end effector from the longitudinal axis; wherein the method comprises: (a) inserting the end effector into a patient; (b) actuating the articulation section by translating the first and second members along the enlarged portions, wherein the act of actuating the articulation section results in bending of the flexible portion of the acoustic waveguide, wherein the act of bending the flexible portion of the acoustic waveguide comprises flexing along the length of the single piece of material forming the narrowed section of the acoustic waveguide to define a curve between the pair of enlarged portions; and (c) actuating the end effector on tissue in the patient, wherein the act of actuating the end effector comprises communicating ultrasonic vibrations along the bent single piece of material forming the narrowed section of the acoustic waveguide.
 2. The method of claim 1, wherein the articulation section includes a collar, wherein an upper portion of the collar is defined by the first member, wherein a lower portion of the collar is defined by the second member.
 3. The method of claim 1, further comprising at least one translatable member secured to the first member.
 4. The method of claim 3, wherein the at least one translatable member is operable to translate to thereby drive articulation of the articulation section.
 5. The method of claim 3, wherein the at least one translatable member comprises a band.
 6. The method of claim 1, further comprising at least one translatable member secured to the second member.
 7. The method of claim 6, wherein the at least one translatable member is operable to translate to thereby drive the clamp arm toward and away from the ultrasonic blade.
 8. The method of claim 1, wherein the articulation section further comprises an outer tube engaged with the first member.
 9. The method of claim 1, wherein the articulation section comprises a set of ribs separated by gaps configured to promote flexing of the articulation section.
 10. The method of claim 1, wherein the articulation drive assembly comprises a pair of translating members, wherein the pair of translating members are operable to translate simultaneously in opposite directions to thereby deflect the end effector from the longitudinal axis.
 11. The method of claim 10, wherein the pair of translating members are further operable to translate simultaneously in the same direction to thereby drive the clamp arm toward and away from the ultrasonic blade.
 12. The method of claim 10, wherein the waveguide includes at least one flange defining a pair of flats, wherein the pair of translating members are positioned at respective flats of the pair of flats.
 13. The method of claim 1, wherein the clamp arm engages the first member in a ball-and-socket configuration.
 14. A method of operating an apparatus, the apparatus comprising: (a) a body assembly; (b) a shaft extending distally from the body assembly, wherein the shaft defines a longitudinal axis; (c) an articulation section coupled with the shaft; (d) an end effector coupled with the articulation section, wherein the end effector comprises: (i) a working element configured to engage tissue, and (ii) a clamp arm operable to pivot toward and away from the working element; and (e) an articulation drive assembly operable to drive articulation of the articulation section to thereby deflect the end effector from the longitudinal axis, wherein the articulation drive assembly comprises: (i) a first translating driver, and (ii) a second translating driver, wherein the first and second translating drivers are operable to translate simultaneously in opposite directions to thereby deflect the end effector from the longitudinal axis, wherein the first and second translating drivers are operable to translate simultaneously in the same direction to thereby drive the clamp arm toward and away from the working element; wherein the method comprises: (a) inserting the end effector into a patient; (b) actuating the articulation section; and (c) actuating the end effector on tissue in the patient.
 15. A method of operating an apparatus, the apparatus comprising: (a) a body assembly; (b) a shaft extending distally from the body assembly, wherein the shaft defines a longitudinal axis; (c) an acoustic waveguide, wherein the waveguide comprises a flexible portion; (d) an articulation section coupled with the shaft, wherein a portion of the articulation section encompasses the flexible portion of the waveguide, wherein the articulation section further comprises: (i) a first member, and (ii) a second member, wherein the second member is longitudinally translatable relative to the first member; (e) an end effector comprising: (i) an ultrasonic blade in acoustic communication with the waveguide, and (ii) a clamp arm, wherein the clamp arm is coupled with the first member and the second member, wherein the clamp arm engages the first member in a ball-and-socket configuration; and (f) an articulation drive assembly operable to drive articulation of the articulation section to thereby deflect the end effector from the longitudinal axis; wherein the method comprises: (a) inserting the end effector into a patient; (b) actuating the articulation section; and (c) actuating the end effector on tissue in the patient.
 16. The method of claim 15, further comprising a first translatable member secured to the first member, wherein the first translatable member is operable to translate to thereby translate the first member and deflect the first member laterally.
 17. The method of claim 16, further comprising a second translatable member secured to the second member, wherein the second translatable member is operable to translate to thereby translate the second member and deflect the second member laterally.
 18. The method of claim 17, wherein at least one of the first and second translatable members is operable to translate to thereby drive the clamp arm toward and away from the ultrasonic blade.
 19. The method of claim 15, wherein the acoustic waveguide is interposed between the first and second members. 